diff --git "a/UsdShade.md" "b/UsdShade.md" new file mode 100644--- /dev/null +++ "b/UsdShade.md" @@ -0,0 +1,4302 @@ + + +UsdShade module — pxr-usd-api 105.1 documentation + +pxr-usd-api + + » +Modules » +UsdShade module + +  + +# UsdShade module + +Summary: The UsdShade module provides schemas and behaviors for creating and binding materials, which encapsulate shading networks. + +Classes: + +AttributeType + +ConnectableAPI +UsdShadeConnectableAPI is an API schema that provides a common interface for creating outputs and making connections between shading parameters and outputs. + +ConnectionModification + +ConnectionSourceInfo +A compact struct to represent a bundle of information about an upstream source attribute. + +CoordSysAPI +UsdShadeCoordSysAPI provides a way to designate, name, and discover coordinate systems. + +Input +This class encapsulates a shader or node-graph input, which is a connectable attribute representing a typed value. + +Material +A Material provides a container into which multiple"render targets"can add data that defines a"shading material"for a renderer. + +MaterialBindingAPI +UsdShadeMaterialBindingAPI is an API schema that provides an interface for binding materials to prims or collections of prims (represented by UsdCollectionAPI objects). + +NodeDefAPI +UsdShadeNodeDefAPI is an API schema that provides attributes for a prim to select a corresponding Shader Node Definition ("Sdr Node"), as well as to look up a runtime entry for that shader node in the form of an SdrShaderNode. + +NodeGraph +A node-graph is a container for shading nodes, as well as other node- graphs. + +Output +This class encapsulates a shader or node-graph output, which is a connectable attribute representing a typed, externally computed value. + +Shader +Base class for all USD shaders. + +ShaderDefParserPlugin +Parses shader definitions represented using USD scene description using the schemas provided by UsdShade. + +ShaderDefUtils +This class contains a set of utility functions used for populating the shader registry with shaders definitions specified using UsdShade schemas. + +Tokens + +Utils +This class contains a set of utility functions used when authoring and querying shading networks. + +class pxr.UsdShade.AttributeType +Attributes: + +Input + +Invalid + +Output + +names + +values + +Input = pxr.UsdShade.AttributeType.Input + +Invalid = pxr.UsdShade.AttributeType.Invalid + +Output = pxr.UsdShade.AttributeType.Output + +names = {'Input': pxr.UsdShade.AttributeType.Input, 'Invalid': pxr.UsdShade.AttributeType.Invalid, 'Output': pxr.UsdShade.AttributeType.Output} + +values = {0: pxr.UsdShade.AttributeType.Invalid, 1: pxr.UsdShade.AttributeType.Input, 2: pxr.UsdShade.AttributeType.Output} + +class pxr.UsdShade.ConnectableAPI +UsdShadeConnectableAPI is an API schema that provides a common +interface for creating outputs and making connections between shading +parameters and outputs. The interface is common to all UsdShade +schemas that support Inputs and Outputs, which currently includes +UsdShadeShader, UsdShadeNodeGraph, and UsdShadeMaterial. +One can construct a UsdShadeConnectableAPI directly from a UsdPrim, or +from objects of any of the schema classes listed above. If it seems +onerous to need to construct a secondary schema object to interact +with Inputs and Outputs, keep in mind that any function whose purpose +is either to walk material/shader networks via their connections, or +to create such networks, can typically be written entirely in terms of +UsdShadeConnectableAPI objects, without needing to care what the +underlying prim type is. +Additionally, the most common UsdShadeConnectableAPI behaviors +(creating Inputs and Outputs, and making connections) are wrapped as +convenience methods on the prim schema classes (creation) and +UsdShadeInput and UsdShadeOutput. +Methods: + +CanConnect +classmethod CanConnect(input, source) -> bool + +ClearSource +classmethod ClearSource(shadingAttr) -> bool + +ClearSources +classmethod ClearSources(shadingAttr) -> bool + +ConnectToSource +classmethod ConnectToSource(shadingAttr, source, mod) -> bool + +CreateInput(name, typeName) +Create an input which can both have a value and be connected. + +CreateOutput(name, typeName) +Create an output, which represents and externally computed, typed value. + +DisconnectSource +classmethod DisconnectSource(shadingAttr, sourceAttr) -> bool + +Get +classmethod Get(stage, path) -> ConnectableAPI + +GetConnectedSource +classmethod GetConnectedSource(shadingAttr, source, sourceName, sourceType) -> bool + +GetConnectedSources +classmethod GetConnectedSources(shadingAttr, invalidSourcePaths) -> list[UsdShadeSourceInfo] + +GetInput(name) +Return the requested input if it exists. + +GetInputs(onlyAuthored) +Returns all inputs on the connectable prim (i.e. + +GetOutput(name) +Return the requested output if it exists. + +GetOutputs(onlyAuthored) +Returns all outputs on the connectable prim (i.e. + +GetRawConnectedSourcePaths +classmethod GetRawConnectedSourcePaths(shadingAttr, sourcePaths) -> bool + +GetSchemaAttributeNames +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] + +HasConnectableAPI +classmethod HasConnectableAPI(schemaType) -> bool + +HasConnectedSource +classmethod HasConnectedSource(shadingAttr) -> bool + +IsContainer() +Returns true if the prim is a container. + +IsSourceConnectionFromBaseMaterial +classmethod IsSourceConnectionFromBaseMaterial(shadingAttr) -> bool + +RequiresEncapsulation() +Returns true if container encapsulation rules should be respected when evaluating connectibility behavior, false otherwise. + +SetConnectedSources +classmethod SetConnectedSources(shadingAttr, sourceInfos) -> bool + +static CanConnect() +classmethod CanConnect(input, source) -> bool +Determines whether the given input can be connected to the given +source attribute, which can be an input or an output. +The result depends on the”connectability”of the input and the source +attributes. Depending on the prim type, this may require the plugin +that defines connectability behavior for that prim type be loaded. +UsdShadeInput::SetConnectability +UsdShadeInput::GetConnectability + +Parameters + +input (Input) – +source (Attribute) – + +CanConnect(input, sourceInput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +sourceInput (Input) – + +CanConnect(input, sourceOutput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +sourceOutput (Output) – + +CanConnect(output, source) -> bool +Determines whether the given output can be connected to the given +source attribute, which can be an input or an output. +An output is considered to be connectable only if it belongs to a +node-graph. Shader outputs are not connectable. +source is an optional argument. If a valid UsdAttribute is +supplied for it, this method will return true only if the source +attribute is owned by a descendant of the node-graph owning the +output. + +Parameters + +output (Output) – +source (Attribute) – + +CanConnect(output, sourceInput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +sourceInput (Input) – + +CanConnect(output, sourceOutput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +sourceOutput (Output) – + +static ClearSource() +classmethod ClearSource(shadingAttr) -> bool +Deprecated +This is the older version that only referenced a single source. Please +use ClearSources instead. + +Parameters +shadingAttr (Attribute) – + +ClearSource(input) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +input (Input) – + +ClearSource(output) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +output (Output) – + +static ClearSources() +classmethod ClearSources(shadingAttr) -> bool +Clears sources for this shading attribute in the current +UsdEditTarget. +Most of the time, what you probably want is DisconnectSource() rather +than this function. +DisconnectSource() + +Parameters +shadingAttr (Attribute) – + +ClearSources(input) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +input (Input) – + +ClearSources(output) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +output (Output) – + +static ConnectToSource() +classmethod ConnectToSource(shadingAttr, source, mod) -> bool +Authors a connection for a given shading attribute shadingAttr . +shadingAttr can represent a parameter, an input or an output. +source is a struct that describes the upstream source attribute +with all the information necessary to make a connection. See the +documentation for UsdShadeConnectionSourceInfo. mod describes the +operation that should be applied to the list of connections. By +default the new connection will replace any existing connections, but +it can add to the list of connections to represent multiple input +connections. +true if a connection was created successfully. false if +shadingAttr or source is invalid. +This method does not verify the connectability of the shading +attribute to the source. Clients must invoke CanConnect() themselves +to ensure compatibility. +The source shading attribute is created if it doesn’t exist already. + +Parameters + +shadingAttr (Attribute) – +source (ConnectionSourceInfo) – +mod (ConnectionModification) – + +ConnectToSource(input, source, mod) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +source (ConnectionSourceInfo) – +mod (ConnectionModification) – + +ConnectToSource(output, source, mod) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +source (ConnectionSourceInfo) – +mod (ConnectionModification) – + +ConnectToSource(shadingAttr, source, sourceName, sourceType, typeName) -> bool +Deprecated +Please use the versions that take a UsdShadeConnectionSourceInfo to +describe the upstream source This is an overloaded member function, +provided for convenience. It differs from the above function only in +what argument(s) it accepts. + +Parameters + +shadingAttr (Attribute) – +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – +typeName (ValueTypeName) – + +ConnectToSource(input, source, sourceName, sourceType, typeName) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – +typeName (ValueTypeName) – + +ConnectToSource(output, source, sourceName, sourceType, typeName) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – +typeName (ValueTypeName) – + +ConnectToSource(shadingAttr, sourcePath) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. +Connect the given shading attribute to the source at path, +sourcePath . +sourcePath should be the fully namespaced property path. +This overload is provided for convenience, for use in contexts where +the prim types are unknown or unavailable. + +Parameters + +shadingAttr (Attribute) – +sourcePath (Path) – + +ConnectToSource(input, sourcePath) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +sourcePath (Path) – + +ConnectToSource(output, sourcePath) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +sourcePath (Path) – + +ConnectToSource(shadingAttr, sourceInput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. +Connect the given shading attribute to the given source input. + +Parameters + +shadingAttr (Attribute) – +sourceInput (Input) – + +ConnectToSource(input, sourceInput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +sourceInput (Input) – + +ConnectToSource(output, sourceInput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +sourceInput (Input) – + +ConnectToSource(shadingAttr, sourceOutput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. +Connect the given shading attribute to the given source output. + +Parameters + +shadingAttr (Attribute) – +sourceOutput (Output) – + +ConnectToSource(input, sourceOutput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +sourceOutput (Output) – + +ConnectToSource(output, sourceOutput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +sourceOutput (Output) – + +CreateInput(name, typeName) → Input +Create an input which can both have a value and be connected. +The attribute representing the input is created in +the”inputs:”namespace. + +Parameters + +name (str) – +typeName (ValueTypeName) – + +CreateOutput(name, typeName) → Output +Create an output, which represents and externally computed, typed +value. +Outputs on node-graphs can be connected. +The attribute representing an output is created in +the”outputs:”namespace. + +Parameters + +name (str) – +typeName (ValueTypeName) – + +static DisconnectSource() +classmethod DisconnectSource(shadingAttr, sourceAttr) -> bool +Disconnect source for this shading attribute. +If sourceAttr is valid it will disconnect the connection to this +upstream attribute. Otherwise it will disconnect all connections by +authoring an empty list of connections for the attribute +shadingAttr . +This may author more scene description than you might expect - we +define the behavior of disconnect to be that, even if a shading +attribute becomes connected in a weaker layer than the current +UsdEditTarget, the attribute will still be disconnected in the +composition, therefore we must”block”it in the current UsdEditTarget. +ConnectToSource() . + +Parameters + +shadingAttr (Attribute) – +sourceAttr (Attribute) – + +DisconnectSource(input, sourceAttr) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +sourceAttr (Attribute) – + +DisconnectSource(output, sourceAttr) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +sourceAttr (Attribute) – + +static Get() +classmethod Get(stage, path) -> ConnectableAPI +Return a UsdShadeConnectableAPI holding the prim adhering to this +schema at path on stage . +If no prim exists at path on stage , or if the prim at that +path does not adhere to this schema, return an invalid schema object. +This is shorthand for the following: +UsdShadeConnectableAPI(stage->GetPrimAtPath(path)); + +Parameters + +stage (Stage) – +path (Path) – + +static GetConnectedSource() +classmethod GetConnectedSource(shadingAttr, source, sourceName, sourceType) -> bool +Deprecated +Shading attributes can have multiple connections and so using +GetConnectedSources is needed in general +Finds the source of a connection for the given shading attribute. +shadingAttr is the shading attribute whose connection we want to +interrogate. source is an output parameter which will be set to +the source connectable prim. sourceName will be set to the name of +the source shading attribute, which may be an input or an output, as +specified by sourceType sourceType will have the type of the +source shading attribute, i.e. whether it is an Input or +Output +true if the shading attribute is connected to a valid, defined +source attribute. false if the shading attribute is not connected +to a single, defined source attribute. +Previously this method would silently return false for multiple +connections. We are changing the behavior of this method to return the +result for the first connection and issue a TfWarn about it. We want +to encourage clients to use GetConnectedSources going forward. +The python wrapping for this method returns a (source, sourceName, +sourceType) tuple if the parameter is connected, else None + +Parameters + +shadingAttr (Attribute) – +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – + +GetConnectedSource(input, source, sourceName, sourceType) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – + +GetConnectedSource(output, source, sourceName, sourceType) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – + +static GetConnectedSources() +classmethod GetConnectedSources(shadingAttr, invalidSourcePaths) -> list[UsdShadeSourceInfo] +Finds the valid sources of connections for the given shading +attribute. +shadingAttr is the shading attribute whose connections we want to +interrogate. invalidSourcePaths is an optional output parameter to +collect the invalid source paths that have not been reported in the +returned vector. +Returns a vector of UsdShadeConnectionSourceInfo structs with +information about each upsteam attribute. If the vector is empty, +there have been no connections. +A valid connection requires the existence of the source attribute and +also requires that the source prim is UsdShadeConnectableAPI +compatible. +The python wrapping returns a tuple with the valid connections first, +followed by the invalid source paths. + +Parameters + +shadingAttr (Attribute) – +invalidSourcePaths (list[SdfPath]) – + +GetConnectedSources(input, invalidSourcePaths) -> list[UsdShadeSourceInfo] +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +invalidSourcePaths (list[SdfPath]) – + +GetConnectedSources(output, invalidSourcePaths) -> list[UsdShadeSourceInfo] +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +invalidSourcePaths (list[SdfPath]) – + +GetInput(name) → Input +Return the requested input if it exists. +name is the unnamespaced base name. + +Parameters +name (str) – + +GetInputs(onlyAuthored) → list[Input] +Returns all inputs on the connectable prim (i.e. +shader or node-graph). Inputs are represented by attributes in +the”inputs:”namespace. If onlyAuthored is true (the default), then +only return authored attributes; otherwise, this also returns un- +authored builtins. + +Parameters +onlyAuthored (bool) – + +GetOutput(name) → Output +Return the requested output if it exists. +name is the unnamespaced base name. + +Parameters +name (str) – + +GetOutputs(onlyAuthored) → list[Output] +Returns all outputs on the connectable prim (i.e. +shader or node-graph). Outputs are represented by attributes in +the”outputs:”namespace. If onlyAuthored is true (the default), +then only return authored attributes; otherwise, this also returns un- +authored builtins. + +Parameters +onlyAuthored (bool) – + +static GetRawConnectedSourcePaths() +classmethod GetRawConnectedSourcePaths(shadingAttr, sourcePaths) -> bool +Deprecated +Please us GetConnectedSources to retrieve multiple connections +Returns the”raw”(authored) connected source paths for the given +shading attribute. + +Parameters + +shadingAttr (Attribute) – +sourcePaths (list[SdfPath]) – + +GetRawConnectedSourcePaths(input, sourcePaths) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +input (Input) – +sourcePaths (list[SdfPath]) – + +GetRawConnectedSourcePaths(output, sourcePaths) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +sourcePaths (list[SdfPath]) – + +static GetSchemaAttributeNames() +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] +Return a vector of names of all pre-declared attributes for this +schema class and all its ancestor classes. +Does not include attributes that may be authored by custom/extended +methods of the schemas involved. + +Parameters +includeInherited (bool) – + +static HasConnectableAPI() +classmethod HasConnectableAPI(schemaType) -> bool +Return true if the schemaType has a valid connectableAPIBehavior +registered, false otherwise. +To check if a prim’s connectableAPI has a behavior defined, use +UsdSchemaBase::operator bool() . + +Parameters +schemaType (Type) – + +HasConnectableAPI() -> bool +Return true if the schema type T has a connectableAPIBehavior +registered, false otherwise. + +static HasConnectedSource() +classmethod HasConnectedSource(shadingAttr) -> bool +Returns true if and only if the shading attribute is currently +connected to at least one valid (defined) source. +If you will be calling GetConnectedSources() afterwards anyways, it +will be much faster to instead check if the returned vector is +empty: +UsdShadeSourceInfoVector connections = + UsdShadeConnectableAPI::GetConnectedSources(attribute); +if (!connections.empty()){ + // process connected attribute +} else { + // process unconnected attribute +} + +Parameters +shadingAttr (Attribute) – + +HasConnectedSource(input) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +input (Input) – + +HasConnectedSource(output) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +output (Output) – + +IsContainer() → bool +Returns true if the prim is a container. +The underlying prim type may provide runtime behavior that defines +whether it is a container. + +static IsSourceConnectionFromBaseMaterial() +classmethod IsSourceConnectionFromBaseMaterial(shadingAttr) -> bool +Returns true if the connection to the given shading attribute’s +source, as returned by UsdShadeConnectableAPI::GetConnectedSource() , +is authored across a specializes arc, which is used to denote a base +material. + +Parameters +shadingAttr (Attribute) – + +IsSourceConnectionFromBaseMaterial(input) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +input (Input) – + +IsSourceConnectionFromBaseMaterial(output) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +output (Output) – + +RequiresEncapsulation() → bool +Returns true if container encapsulation rules should be respected when +evaluating connectibility behavior, false otherwise. +The underlying prim type may provide runtime behavior that defines if +encapsulation rules are respected or not. + +static SetConnectedSources() +classmethod SetConnectedSources(shadingAttr, sourceInfos) -> bool +Authors a list of connections for a given shading attribute +shadingAttr . +shadingAttr can represent a parameter, an input or an output. +sourceInfos is a vector of structs that describes the upstream +source attributes with all the information necessary to make all the +connections. See the documentation for UsdShadeConnectionSourceInfo. +true if all connection were created successfully. false if the +shadingAttr or one of the sources are invalid. +A valid connection is one that has a valid +UsdShadeConnectionSourceInfo , which requires the existence of the +upstream source prim. It does not require the existence of the source +attribute as it will be create if necessary. + +Parameters + +shadingAttr (Attribute) – +sourceInfos (list[ConnectionSourceInfo]) – + +class pxr.UsdShade.ConnectionModification +Attributes: + +Append + +Prepend + +Replace + +names + +values + +Append = pxr.UsdShade.ConnectionModification.Append + +Prepend = pxr.UsdShade.ConnectionModification.Prepend + +Replace = pxr.UsdShade.ConnectionModification.Replace + +names = {'Append': pxr.UsdShade.ConnectionModification.Append, 'Prepend': pxr.UsdShade.ConnectionModification.Prepend, 'Replace': pxr.UsdShade.ConnectionModification.Replace} + +values = {0: pxr.UsdShade.ConnectionModification.Replace, 1: pxr.UsdShade.ConnectionModification.Prepend, 2: pxr.UsdShade.ConnectionModification.Append} + +class pxr.UsdShade.ConnectionSourceInfo +A compact struct to represent a bundle of information about an +upstream source attribute. +Methods: + +IsValid() +Return true if this source info is valid for setting up a connection. + +Attributes: + +source + +sourceName + +sourceType + +typeName + +IsValid() → bool +Return true if this source info is valid for setting up a connection. + +property source + +property sourceName + +property sourceType + +property typeName + +class pxr.UsdShade.CoordSysAPI +UsdShadeCoordSysAPI provides a way to designate, name, and discover +coordinate systems. +Coordinate systems are implicitly established by UsdGeomXformable +prims, using their local space. That coordinate system may be bound +(i.e., named) from another prim. The binding is encoded as a single- +target relationship in the”coordSys:”namespace. Coordinate system +bindings apply to descendants of the prim where the binding is +expressed, but names may be re-bound by descendant prims. +Named coordinate systems are useful in shading workflows. An example +is projection paint, which projects a texture from a certain view (the +paint coordinate system). Using the paint coordinate frame avoids the +need to assign a UV set to the object, and can be a concise way to +project paint across a collection of objects with a single shared +paint coordinate system. +This is a non-applied API schema. +Methods: + +Bind(name, path) +Bind the name to the given path. + +BlockBinding(name) +Block the indicated coordinate system binding on this prim by blocking targets on the underlying relationship. + +CanContainPropertyName +classmethod CanContainPropertyName(name) -> bool + +ClearBinding(name, removeSpec) +Clear the indicated coordinate system binding on this prim from the current edit target. + +FindBindingsWithInheritance() +Find the list of coordinate system bindings that apply to this prim, including inherited bindings. + +Get +classmethod Get(stage, path) -> CoordSysAPI + +GetCoordSysRelationshipName +classmethod GetCoordSysRelationshipName(coordSysName) -> str + +GetLocalBindings() +Get the list of coordinate system bindings local to this prim. + +GetSchemaAttributeNames +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] + +HasLocalBindings() +Returns true if the prim has local coordinate system binding opinions. + +Bind(name, path) → bool +Bind the name to the given path. +The prim at the given path is expected to be UsdGeomXformable, in +order for the binding to be succesfully resolved. + +Parameters + +name (str) – +path (Path) – + +BlockBinding(name) → bool +Block the indicated coordinate system binding on this prim by blocking +targets on the underlying relationship. + +Parameters +name (str) – + +static CanContainPropertyName() +classmethod CanContainPropertyName(name) -> bool +Test whether a given name contains the”coordSys:”prefix. + +Parameters +name (str) – + +ClearBinding(name, removeSpec) → bool +Clear the indicated coordinate system binding on this prim from the +current edit target. +Only remove the spec if removeSpec is true (leave the spec to +preserve meta-data we may have intentionally authored on the +relationship) + +Parameters + +name (str) – +removeSpec (bool) – + +FindBindingsWithInheritance() → list[Binding] +Find the list of coordinate system bindings that apply to this prim, +including inherited bindings. +This computation examines this prim and ancestors for the strongest +binding for each name. A binding expressed by a child prim supercedes +bindings on ancestors. +Note that this API does not validate the prims at the target paths; +they may be of incorrect type, or missing entirely. +Binding relationships with no resolved targets are skipped. + +static Get() +classmethod Get(stage, path) -> CoordSysAPI +Return a UsdShadeCoordSysAPI holding the prim adhering to this schema +at path on stage . +If no prim exists at path on stage , or if the prim at that +path does not adhere to this schema, return an invalid schema object. +This is shorthand for the following: +UsdShadeCoordSysAPI(stage->GetPrimAtPath(path)); + +Parameters + +stage (Stage) – +path (Path) – + +static GetCoordSysRelationshipName() +classmethod GetCoordSysRelationshipName(coordSysName) -> str +Returns the fully namespaced coordinate system relationship name, +given the coordinate system name. + +Parameters +coordSysName (str) – + +GetLocalBindings() → list[Binding] +Get the list of coordinate system bindings local to this prim. +This does not process inherited bindings. It does not validate that a +prim exists at the indicated path. If the binding relationship has +multiple targets, only the first is used. + +static GetSchemaAttributeNames() +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] +Return a vector of names of all pre-declared attributes for this +schema class and all its ancestor classes. +Does not include attributes that may be authored by custom/extended +methods of the schemas involved. + +Parameters +includeInherited (bool) – + +HasLocalBindings() → bool +Returns true if the prim has local coordinate system binding opinions. +Note that the resulting binding list may still be empty. + +class pxr.UsdShade.Input +This class encapsulates a shader or node-graph input, which is a +connectable attribute representing a typed value. +Methods: + +CanConnect(source) +Determines whether this Input can be connected to the given source attribute, which can be an input or an output. + +ClearConnectability() +Clears any authored connectability on the Input. + +ClearSdrMetadata() +Clears any"sdrMetadata"value authored on the Input in the current EditTarget. + +ClearSdrMetadataByKey(key) +Clears the entry corresponding to the given key in the"sdrMetadata"dictionary authored in the current EditTarget. + +ClearSource() +Deprecated + +ClearSources() +Clears sources for this Input in the current UsdEditTarget. + +ConnectToSource(source, mod) +Authors a connection for this Input. + +DisconnectSource(sourceAttr) +Disconnect source for this Input. + +Get(value, time) +Convenience wrapper for the templated UsdAttribute::Get() . + +GetAttr() +Explicit UsdAttribute extractor. + +GetBaseName() +Returns the name of the input. + +GetConnectability() +Returns the connectability of the Input. + +GetConnectedSource(source, sourceName, ...) +Deprecated + +GetConnectedSources(invalidSourcePaths) +Finds the valid sources of connections for the Input. + +GetDisplayGroup() +Get the displayGroup metadata for this Input, i.e. + +GetDocumentation() +Get documentation string for this Input. + +GetFullName() +Get the name of the attribute associated with the Input. + +GetPrim() +Get the prim that the input belongs to. + +GetRawConnectedSourcePaths(sourcePaths) +Deprecated + +GetRenderType() +Return this Input's specialized renderType, or an empty token if none was authored. + +GetSdrMetadata() +Returns this Input's composed"sdrMetadata"dictionary as a NdrTokenMap. + +GetSdrMetadataByKey(key) +Returns the value corresponding to key in the composed sdrMetadata dictionary. + +GetTypeName() +Get the"scene description"value type name of the attribute associated with the Input. + +GetValueProducingAttribute(attrType) +Deprecated + +GetValueProducingAttributes(shaderOutputsOnly) +Find what is connected to this Input recursively. + +HasConnectedSource() +Returns true if and only if this Input is currently connected to a valid (defined) source. + +HasRenderType() +Return true if a renderType has been specified for this Input. + +HasSdrMetadata() +Returns true if the Input has a non-empty composed"sdrMetadata"dictionary value. + +HasSdrMetadataByKey(key) +Returns true if there is a value corresponding to the given key in the composed"sdrMetadata"dictionary. + +IsInput +classmethod IsInput(attr) -> bool + +IsInterfaceInputName +classmethod IsInterfaceInputName(name) -> bool + +IsSourceConnectionFromBaseMaterial() +Returns true if the connection to this Input's source, as returned by GetConnectedSource() , is authored across a specializes arc, which is used to denote a base material. + +Set(value, time) +Set a value for the Input at time . + +SetConnectability(connectability) +Set the connectability of the Input. + +SetConnectedSources(sourceInfos) +Connects this Input to the given sources, sourceInfos . + +SetDisplayGroup(displayGroup) +Set the displayGroup metadata for this Input, i.e. + +SetDocumentation(docs) +Set documentation string for this Input. + +SetRenderType(renderType) +Specify an alternative, renderer-specific type to use when emitting/translating this Input, rather than translating based on its GetTypeName() + +SetSdrMetadata(sdrMetadata) +Authors the given sdrMetadata value on this Input at the current EditTarget. + +SetSdrMetadataByKey(key, value) +Sets the value corresponding to key to the given string value , in the Input's"sdrMetadata"dictionary at the current EditTarget. + +CanConnect(source) → bool +Determines whether this Input can be connected to the given source +attribute, which can be an input or an output. +UsdShadeConnectableAPI::CanConnect + +Parameters +source (Attribute) – + +CanConnect(sourceInput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +sourceInput (Input) – + +CanConnect(sourceOutput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +sourceOutput (Output) – + +ClearConnectability() → bool +Clears any authored connectability on the Input. + +ClearSdrMetadata() → None +Clears any”sdrMetadata”value authored on the Input in the current +EditTarget. + +ClearSdrMetadataByKey(key) → None +Clears the entry corresponding to the given key in +the”sdrMetadata”dictionary authored in the current EditTarget. + +Parameters +key (str) – + +ClearSource() → bool +Deprecated + +ClearSources() → bool +Clears sources for this Input in the current UsdEditTarget. +Most of the time, what you probably want is DisconnectSource() rather +than this function. +UsdShadeConnectableAPI::ClearSources + +ConnectToSource(source, mod) → bool +Authors a connection for this Input. +source is a struct that describes the upstream source attribute +with all the information necessary to make a connection. See the +documentation for UsdShadeConnectionSourceInfo. mod describes the +operation that should be applied to the list of connections. By +default the new connection will replace any existing connections, but +it can add to the list of connections to represent multiple input +connections. +true if a connection was created successfully. false if this +input or source is invalid. +This method does not verify the connectability of the shading +attribute to the source. Clients must invoke CanConnect() themselves +to ensure compatibility. +The source shading attribute is created if it doesn’t exist already. +UsdShadeConnectableAPI::ConnectToSource + +Parameters + +source (ConnectionSourceInfo) – +mod (ConnectionModification) – + +ConnectToSource(source, sourceName, sourceType, typeName) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – +typeName (ValueTypeName) – + +ConnectToSource(sourcePath) -> bool +Authors a connection for this Input to the source at the given path. +UsdShadeConnectableAPI::ConnectToSource + +Parameters +sourcePath (Path) – + +ConnectToSource(sourceInput) -> bool +Connects this Input to the given input, sourceInput . +UsdShadeConnectableAPI::ConnectToSource + +Parameters +sourceInput (Input) – + +ConnectToSource(sourceOutput) -> bool +Connects this Input to the given output, sourceOutput . +UsdShadeConnectableAPI::ConnectToSource + +Parameters +sourceOutput (Output) – + +DisconnectSource(sourceAttr) → bool +Disconnect source for this Input. +If sourceAttr is valid, only a connection to the specified +attribute is disconnected, otherwise all connections are removed. +UsdShadeConnectableAPI::DisconnectSource + +Parameters +sourceAttr (Attribute) – + +Get(value, time) → bool +Convenience wrapper for the templated UsdAttribute::Get() . + +Parameters + +value (T) – +time (TimeCode) – + +Get(value, time) -> bool +Convenience wrapper for VtValue version of UsdAttribute::Get() . + +Parameters + +value (VtValue) – +time (TimeCode) – + +GetAttr() → Attribute +Explicit UsdAttribute extractor. + +GetBaseName() → str +Returns the name of the input. +We call this the base name since it strips off the”inputs:”namespace +prefix from the attribute name, and returns it. + +GetConnectability() → str +Returns the connectability of the Input. +SetConnectability() + +GetConnectedSource(source, sourceName, sourceType) → bool +Deprecated + +Parameters + +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – + +GetConnectedSources(invalidSourcePaths) → list[SourceInfo] +Finds the valid sources of connections for the Input. +invalidSourcePaths is an optional output parameter to collect the +invalid source paths that have not been reported in the returned +vector. +Returns a vector of UsdShadeConnectionSourceInfo structs with +information about each upsteam attribute. If the vector is empty, +there have been no valid connections. +A valid connection requires the existence of the source attribute and +also requires that the source prim is UsdShadeConnectableAPI +compatible. +The python wrapping returns a tuple with the valid connections first, +followed by the invalid source paths. +UsdShadeConnectableAPI::GetConnectedSources + +Parameters +invalidSourcePaths (list[SdfPath]) – + +GetDisplayGroup() → str +Get the displayGroup metadata for this Input, i.e. +hint for the location and nesting of the attribute. +UsdProperty::GetDisplayGroup() , UsdProperty::GetNestedDisplayGroup() + +GetDocumentation() → str +Get documentation string for this Input. +UsdObject::GetDocumentation() + +GetFullName() → str +Get the name of the attribute associated with the Input. + +GetPrim() → Prim +Get the prim that the input belongs to. + +GetRawConnectedSourcePaths(sourcePaths) → bool +Deprecated +Returns the”raw”(authored) connected source paths for this Input. +UsdShadeConnectableAPI::GetRawConnectedSourcePaths + +Parameters +sourcePaths (list[SdfPath]) – + +GetRenderType() → str +Return this Input’s specialized renderType, or an empty token if none +was authored. +SetRenderType() + +GetSdrMetadata() → NdrTokenMap +Returns this Input’s composed”sdrMetadata”dictionary as a NdrTokenMap. + +GetSdrMetadataByKey(key) → str +Returns the value corresponding to key in the composed +sdrMetadata dictionary. + +Parameters +key (str) – + +GetTypeName() → ValueTypeName +Get the”scene description”value type name of the attribute associated +with the Input. + +GetValueProducingAttribute(attrType) → Attribute +Deprecated +in favor of calling GetValueProducingAttributes + +Parameters +attrType (AttributeType) – + +GetValueProducingAttributes(shaderOutputsOnly) → list[UsdShadeAttribute] +Find what is connected to this Input recursively. +UsdShadeUtils::GetValueProducingAttributes + +Parameters +shaderOutputsOnly (bool) – + +HasConnectedSource() → bool +Returns true if and only if this Input is currently connected to a +valid (defined) source. +UsdShadeConnectableAPI::HasConnectedSource + +HasRenderType() → bool +Return true if a renderType has been specified for this Input. +SetRenderType() + +HasSdrMetadata() → bool +Returns true if the Input has a non-empty +composed”sdrMetadata”dictionary value. + +HasSdrMetadataByKey(key) → bool +Returns true if there is a value corresponding to the given key in +the composed”sdrMetadata”dictionary. + +Parameters +key (str) – + +static IsInput() +classmethod IsInput(attr) -> bool +Test whether a given UsdAttribute represents a valid Input, which +implies that creating a UsdShadeInput from the attribute will succeed. +Success implies that attr.IsDefined() is true. + +Parameters +attr (Attribute) – + +static IsInterfaceInputName() +classmethod IsInterfaceInputName(name) -> bool +Test if this name has a namespace that indicates it could be an input. + +Parameters +name (str) – + +IsSourceConnectionFromBaseMaterial() → bool +Returns true if the connection to this Input’s source, as returned by +GetConnectedSource() , is authored across a specializes arc, which is +used to denote a base material. +UsdShadeConnectableAPI::IsSourceConnectionFromBaseMaterial + +Set(value, time) → bool +Set a value for the Input at time . + +Parameters + +value (VtValue) – +time (TimeCode) – + +Set(value, time) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. +Set a value of the Input at time . + +Parameters + +value (T) – +time (TimeCode) – + +SetConnectability(connectability) → bool +Set the connectability of the Input. +In certain shading data models, there is a need to distinguish which +inputs can vary over a surface from those that must be +uniform. This is accomplished in UsdShade by limiting the +connectability of the input. This is done by setting +the”connectability”metadata on the associated attribute. +Connectability of an Input can be set to UsdShadeTokens->full or +UsdShadeTokens->interfaceOnly. + +full implies that the Input can be connected to any other +Input or Output. +interfaceOnly implies that the Input can only be connected to +a NodeGraph Input (which represents an interface override, not a +render-time dataflow connection), or another Input whose +connectability is also”interfaceOnly”. +The default connectability of an input is UsdShadeTokens->full. + +SetConnectability() + +Parameters +connectability (str) – + +SetConnectedSources(sourceInfos) → bool +Connects this Input to the given sources, sourceInfos . +UsdShadeConnectableAPI::SetConnectedSources + +Parameters +sourceInfos (list[ConnectionSourceInfo]) – + +SetDisplayGroup(displayGroup) → bool +Set the displayGroup metadata for this Input, i.e. +hinting for the location and nesting of the attribute. +Note for an input representing a nested SdrShaderProperty, its +expected to have the scope delimited by a”:”. +UsdProperty::SetDisplayGroup() , UsdProperty::SetNestedDisplayGroup() +SdrShaderProperty::GetPage() + +Parameters +displayGroup (str) – + +SetDocumentation(docs) → bool +Set documentation string for this Input. +UsdObject::SetDocumentation() + +Parameters +docs (str) – + +SetRenderType(renderType) → bool +Specify an alternative, renderer-specific type to use when +emitting/translating this Input, rather than translating based on its +GetTypeName() +For example, we set the renderType to”struct”for Inputs that are of +renderman custom struct types. +true on success. + +Parameters +renderType (str) – + +SetSdrMetadata(sdrMetadata) → None +Authors the given sdrMetadata value on this Input at the current +EditTarget. + +Parameters +sdrMetadata (NdrTokenMap) – + +SetSdrMetadataByKey(key, value) → None +Sets the value corresponding to key to the given string value +, in the Input’s”sdrMetadata”dictionary at the current EditTarget. + +Parameters + +key (str) – +value (str) – + +class pxr.UsdShade.Material +A Material provides a container into which multiple”render targets”can +add data that defines a”shading material”for a renderer. Typically +this consists of one or more UsdRelationship properties that target +other prims of type Shader - though a target/client is free to add +any data that is suitable. We strongly advise that all targets +adopt the convention that all properties be prefixed with a namespace +that identifies the target, e.g.”rel ri:surface =”. +In the UsdShading model, geometry expresses a binding to a single +Material or to a set of Materials partitioned by UsdGeomSubsets +defined beneath the geometry; it is legal to bind a Material at the +root (or other sub-prim) of a model, and then bind a different +Material to individual gprims, but the meaning of inheritance +and”ancestral overriding”of Material bindings is left to each render- +target to determine. Since UsdGeom has no concept of shading, we +provide the API for binding and unbinding geometry on the API schema +UsdShadeMaterialBindingAPI. +The entire power of USD VariantSets and all the other composition +operators can leveraged when encoding shading variation. +UsdShadeMaterial provides facilities for a particular way of +building”Material variants”in which neither the identity of the +Materials themselves nor the geometry Material-bindings need to change +- instead we vary the targeted networks, interface values, and even +parameter values within a single variantSet. See Authoring Material +Variations for more details. +UsdShade requires that all of the shaders that”belong”to the Material +live under the Material in namespace. This supports powerful, easy +reuse of Materials, because it allows us to reference a Material +from one asset (the asset might be a module of Materials) into +another asset: USD references compose all descendant prims of the +reference target into the referencer’s namespace, which means that all +of the referenced Material’s shader networks will come along with the +Material. When referenced in this way, Materials can also be +instanced, for ease of deduplication and compactness. Finally, +Material encapsulation also allows us to specialize child materials +from parent materials. +For any described attribute Fallback Value or Allowed Values +below that are text/tokens, the actual token is published and defined +in UsdShadeTokens. So to set an attribute to the value”rightHanded”, +use UsdShadeTokens->rightHanded as the value. +Methods: + +ClearBaseMaterial() +Clear the base Material of this Material. + +ComputeDisplacementSource(renderContext, ...) +Deprecated + +ComputeSurfaceSource(renderContext, ...) +Deprecated + +ComputeVolumeSource(renderContext, ...) +Deprecated + +CreateDisplacementAttr(defaultValue, ...) +See GetDisplacementAttr() , and also Create vs Get Property Methods for when to use Get vs Create. + +CreateDisplacementOutput(renderContext) +Creates and returns the"displacement"output on this material for the specified renderContext . + +CreateMasterMaterialVariant +classmethod CreateMasterMaterialVariant(masterPrim, MaterialPrims, masterVariantSetName) -> bool + +CreateSurfaceAttr(defaultValue, writeSparsely) +See GetSurfaceAttr() , and also Create vs Get Property Methods for when to use Get vs Create. + +CreateSurfaceOutput(renderContext) +Creates and returns the"surface"output on this material for the specified renderContext . + +CreateVolumeAttr(defaultValue, writeSparsely) +See GetVolumeAttr() , and also Create vs Get Property Methods for when to use Get vs Create. + +CreateVolumeOutput(renderContext) +Creates and returns the"volume"output on this material for the specified renderContext . + +Define +classmethod Define(stage, path) -> Material + +Get +classmethod Get(stage, path) -> Material + +GetBaseMaterial() +Get the path to the base Material of this Material. + +GetBaseMaterialPath() +Get the base Material of this Material. + +GetDisplacementAttr() +Represents the universal"displacement"output terminal of a material. + +GetDisplacementOutput(renderContext) +Returns the"displacement"output of this material for the specified renderContext. + +GetDisplacementOutputs() +Returns the"displacement"outputs of this material for all available renderContexts. + +GetEditContextForVariant(...) +Helper function for configuring a UsdStage 's UsdEditTarget to author Material variations. + +GetMaterialVariant() +Return a UsdVariantSet object for interacting with the Material variant variantSet. + +GetSchemaAttributeNames +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] + +GetSurfaceAttr() +Represents the universal"surface"output terminal of a material. + +GetSurfaceOutput(renderContext) +Returns the"surface"output of this material for the specified renderContext . + +GetSurfaceOutputs() +Returns the"surface"outputs of this material for all available renderContexts. + +GetVolumeAttr() +Represents the universal"volume"output terminal of a material. + +GetVolumeOutput(renderContext) +Returns the"volume"output of this material for the specified renderContext. + +GetVolumeOutputs() +Returns the"volume"outputs of this material for all available renderContexts. + +HasBaseMaterial() + +SetBaseMaterial(baseMaterial) +Set the base Material of this Material. + +SetBaseMaterialPath(baseMaterialPath) +Set the path to the base Material of this Material. + +ClearBaseMaterial() → None +Clear the base Material of this Material. + +ComputeDisplacementSource(renderContext, sourceName, sourceType) → Shader +Deprecated +Use the form that takes a TfTokenVector or renderContexts + +Parameters + +renderContext (str) – +sourceName (str) – +sourceType (AttributeType) – + +ComputeDisplacementSource(contextVector, sourceName, sourceType) -> Shader +Computes the resolved”displacement”output source for the given +contextVector . +Using the earliest renderContext in the contextVector that produces a +valid Shader object. +If a”displacement”output corresponding to each of the renderContexts +does not exist or is not connected to a valid source, then this +checks the universal displacement output. +Returns an empty Shader object if there is no valid displacement +output source for any of the renderContexts in the contextVector . +The python version of this method returns a tuple containing three +elements (the source displacement shader, sourceName, sourceType). + +Parameters + +contextVector (list[TfToken]) – +sourceName (str) – +sourceType (AttributeType) – + +ComputeSurfaceSource(renderContext, sourceName, sourceType) → Shader +Deprecated +Use the form that takes a TfTokenVector or renderContexts. + +Parameters + +renderContext (str) – +sourceName (str) – +sourceType (AttributeType) – + +ComputeSurfaceSource(contextVector, sourceName, sourceType) -> Shader +Computes the resolved”surface”output source for the given +contextVector . +Using the earliest renderContext in the contextVector that produces a +valid Shader object. +If a”surface”output corresponding to each of the renderContexts does +not exist or is not connected to a valid source, then this checks +the universal surface output. +Returns an empty Shader object if there is no valid surface output +source for any of the renderContexts in the contextVector . The +python version of this method returns a tuple containing three +elements (the source surface shader, sourceName, sourceType). + +Parameters + +contextVector (list[TfToken]) – +sourceName (str) – +sourceType (AttributeType) – + +ComputeVolumeSource(renderContext, sourceName, sourceType) → Shader +Deprecated +Use the form that takes a TfTokenVector or renderContexts + +Parameters + +renderContext (str) – +sourceName (str) – +sourceType (AttributeType) – + +ComputeVolumeSource(contextVector, sourceName, sourceType) -> Shader +Computes the resolved”volume”output source for the given +contextVector . +Using the earliest renderContext in the contextVector that produces a +valid Shader object. +If a”volume”output corresponding to each of the renderContexts does +not exist or is not connected to a valid source, then this checks +the universal volume output. +Returns an empty Shader object if there is no valid volume output +output source for any of the renderContexts in the contextVector . +The python version of this method returns a tuple containing three +elements (the source volume shader, sourceName, sourceType). + +Parameters + +contextVector (list[TfToken]) – +sourceName (str) – +sourceType (AttributeType) – + +CreateDisplacementAttr(defaultValue, writeSparsely) → Attribute +See GetDisplacementAttr() , and also Create vs Get Property Methods +for when to use Get vs Create. +If specified, author defaultValue as the attribute’s default, +sparsely (when it makes sense to do so) if writeSparsely is +true - the default for writeSparsely is false . + +Parameters + +defaultValue (VtValue) – +writeSparsely (bool) – + +CreateDisplacementOutput(renderContext) → Output +Creates and returns the”displacement”output on this material for the +specified renderContext . +If the output already exists on the material, it is returned and no +authoring is performed. The returned output will always have the +requested renderContext. + +Parameters +renderContext (str) – + +static CreateMasterMaterialVariant() +classmethod CreateMasterMaterialVariant(masterPrim, MaterialPrims, masterVariantSetName) -> bool +Create a variantSet on masterPrim that will set the +MaterialVariant on each of the given MaterialPrims. +The variantSet, whose name can be specified with +masterVariantSetName and defaults to the same MaterialVariant name +created on Materials by GetEditContextForVariant() , will have the +same variants as the Materials, and each Master variant will set every +MaterialPrims' MaterialVariant selection to the same variant as +the master. Thus, it allows all Materials to be switched with a single +variant selection, on masterPrim . +If masterPrim is an ancestor of any given member of +MaterialPrims , then we will author variant selections directly on +the MaterialPrims. However, it is often preferable to create a master +MaterialVariant in a separately rooted tree from the MaterialPrims, so +that it can be layered more strongly on top of the Materials. +Therefore, for any MaterialPrim in a different tree than masterPrim, +we will create”overs”as children of masterPrim that recreate the path +to the MaterialPrim, substituting masterPrim’s full path for the +MaterialPrim’s root path component. +Upon successful completion, the new variantSet we created on +masterPrim will have its variant selection authored to +the”last”variant (determined lexicographically). It is up to the +calling client to either UsdVariantSet::ClearVariantSelection() on +masterPrim , or set the selection to the desired default setting. +Return true on success. It is an error if any of Materials +have a different set of variants for the MaterialVariant than the +others. + +Parameters + +masterPrim (Prim) – +MaterialPrims (list[Prim]) – +masterVariantSetName (str) – + +CreateSurfaceAttr(defaultValue, writeSparsely) → Attribute +See GetSurfaceAttr() , and also Create vs Get Property Methods for +when to use Get vs Create. +If specified, author defaultValue as the attribute’s default, +sparsely (when it makes sense to do so) if writeSparsely is +true - the default for writeSparsely is false . + +Parameters + +defaultValue (VtValue) – +writeSparsely (bool) – + +CreateSurfaceOutput(renderContext) → Output +Creates and returns the”surface”output on this material for the +specified renderContext . +If the output already exists on the material, it is returned and no +authoring is performed. The returned output will always have the +requested renderContext. + +Parameters +renderContext (str) – + +CreateVolumeAttr(defaultValue, writeSparsely) → Attribute +See GetVolumeAttr() , and also Create vs Get Property Methods for when +to use Get vs Create. +If specified, author defaultValue as the attribute’s default, +sparsely (when it makes sense to do so) if writeSparsely is +true - the default for writeSparsely is false . + +Parameters + +defaultValue (VtValue) – +writeSparsely (bool) – + +CreateVolumeOutput(renderContext) → Output +Creates and returns the”volume”output on this material for the +specified renderContext . +If the output already exists on the material, it is returned and no +authoring is performed. The returned output will always have the +requested renderContext. + +Parameters +renderContext (str) – + +static Define() +classmethod Define(stage, path) -> Material +Attempt to ensure a UsdPrim adhering to this schema at path is +defined (according to UsdPrim::IsDefined() ) on this stage. +If a prim adhering to this schema at path is already defined on +this stage, return that prim. Otherwise author an SdfPrimSpec with +specifier == SdfSpecifierDef and this schema’s prim type name for +the prim at path at the current EditTarget. Author SdfPrimSpec s +with specifier == SdfSpecifierDef and empty typeName at the +current EditTarget for any nonexistent, or existing but not Defined +ancestors. +The given path must be an absolute prim path that does not contain +any variant selections. +If it is impossible to author any of the necessary PrimSpecs, (for +example, in case path cannot map to the current UsdEditTarget ‘s +namespace) issue an error and return an invalid UsdPrim. +Note that this method may return a defined prim whose typeName does +not specify this schema class, in case a stronger typeName opinion +overrides the opinion at the current EditTarget. + +Parameters + +stage (Stage) – +path (Path) – + +static Get() +classmethod Get(stage, path) -> Material +Return a UsdShadeMaterial holding the prim adhering to this schema at +path on stage . +If no prim exists at path on stage , or if the prim at that +path does not adhere to this schema, return an invalid schema object. +This is shorthand for the following: +UsdShadeMaterial(stage->GetPrimAtPath(path)); + +Parameters + +stage (Stage) – +path (Path) – + +GetBaseMaterial() → Material +Get the path to the base Material of this Material. +If there is no base Material, an empty Material is returned + +GetBaseMaterialPath() → Path +Get the base Material of this Material. +If there is no base Material, an empty path is returned + +GetDisplacementAttr() → Attribute +Represents the universal”displacement”output terminal of a material. +Declaration +token outputs:displacement +C++ Type +TfToken +Usd Type +SdfValueTypeNames->Token + +GetDisplacementOutput(renderContext) → Output +Returns the”displacement”output of this material for the specified +renderContext. +The returned output will always have the requested renderContext. +An invalid output is returned if an output corresponding to the +requested specific-renderContext does not exist. +UsdShadeMaterial::ComputeDisplacementSource() + +Parameters +renderContext (str) – + +GetDisplacementOutputs() → list[Output] +Returns the”displacement”outputs of this material for all available +renderContexts. +The returned vector will include all authored”displacement”outputs +with the universal renderContext output first, if present. Outputs +are returned regardless of whether they are connected to a valid +source. + +GetEditContextForVariant(MaterialVariantName, layer) → tuple[Stage, EditTarget] +Helper function for configuring a UsdStage ‘s UsdEditTarget to author +Material variations. +Takes care of creating the Material variantSet and specified variant, +if necessary. +Let’s assume that we are authoring Materials into the Stage’s current +UsdEditTarget, and that we are iterating over the variations of a +UsdShadeMaterial clothMaterial, and currVariant is the variant we +are processing (e.g.”denim”). +In C++, then, we would use the following pattern: +{ + UsdEditContext ctxt(clothMaterial.GetEditContextForVariant(currVariant)); + + // All USD mutation of the UsdStage on which clothMaterial sits will + // now go "inside" the currVariant of the "MaterialVariant" variantSet +} + +In python, the pattern is: +with clothMaterial.GetEditContextForVariant(currVariant): + # Now sending mutations to currVariant + +If layer is specified, then we will use it, rather than the +stage’s current UsdEditTarget ‘s layer as the destination layer for +the edit context we are building. If layer does not actually +contribute to the Material prim’s definition, any editing will have no +effect on this Material. +Note: As just stated, using this method involves authoring a +selection for the MaterialVariant in the stage’s current EditTarget. +When client is done authoring variations on this prim, they will +likely want to either UsdVariantSet::SetVariantSelection() to the +appropriate default selection, or possibly +UsdVariantSet::ClearVariantSelection() on the +UsdShadeMaterial::GetMaterialVariant() UsdVariantSet. +UsdVariantSet::GetVariantEditContext() + +Parameters + +MaterialVariantName (str) – +layer (Layer) – + +GetMaterialVariant() → VariantSet +Return a UsdVariantSet object for interacting with the Material +variant variantSet. + +static GetSchemaAttributeNames() +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] +Return a vector of names of all pre-declared attributes for this +schema class and all its ancestor classes. +Does not include attributes that may be authored by custom/extended +methods of the schemas involved. + +Parameters +includeInherited (bool) – + +GetSurfaceAttr() → Attribute +Represents the universal”surface”output terminal of a material. +Declaration +token outputs:surface +C++ Type +TfToken +Usd Type +SdfValueTypeNames->Token + +GetSurfaceOutput(renderContext) → Output +Returns the”surface”output of this material for the specified +renderContext . +The returned output will always have the requested renderContext. +An invalid output is returned if an output corresponding to the +requested specific-renderContext does not exist. +UsdShadeMaterial::ComputeSurfaceSource() + +Parameters +renderContext (str) – + +GetSurfaceOutputs() → list[Output] +Returns the”surface”outputs of this material for all available +renderContexts. +The returned vector will include all authored”surface”outputs with the +universal renderContext output first, if present. Outputs are +returned regardless of whether they are connected to a valid source. + +GetVolumeAttr() → Attribute +Represents the universal”volume”output terminal of a material. +Declaration +token outputs:volume +C++ Type +TfToken +Usd Type +SdfValueTypeNames->Token + +GetVolumeOutput(renderContext) → Output +Returns the”volume”output of this material for the specified +renderContext. +The returned output will always have the requested renderContext. +An invalid output is returned if an output corresponding to the +requested specific-renderContext does not exist. +UsdShadeMaterial::ComputeVolumeSource() + +Parameters +renderContext (str) – + +GetVolumeOutputs() → list[Output] +Returns the”volume”outputs of this material for all available +renderContexts. +The returned vector will include all authored”volume”outputs with the +universal renderContext output first, if present. Outputs are +returned regardless of whether they are connected to a valid source. + +HasBaseMaterial() → bool + +SetBaseMaterial(baseMaterial) → None +Set the base Material of this Material. +An empty Material is equivalent to clearing the base Material. + +Parameters +baseMaterial (Material) – + +SetBaseMaterialPath(baseMaterialPath) → None +Set the path to the base Material of this Material. +An empty path is equivalent to clearing the base Material. + +Parameters +baseMaterialPath (Path) – + +class pxr.UsdShade.MaterialBindingAPI +UsdShadeMaterialBindingAPI is an API schema that provides an interface +for binding materials to prims or collections of prims (represented by +UsdCollectionAPI objects). +In the USD shading model, each renderable gprim computes a single +resolved Material that will be used to shade the gprim +(exceptions, of course, for gprims that possess UsdGeomSubsets, as +each subset can be shaded by a different Material). A gprim and each +of its ancestor prims can possess, through the MaterialBindingAPI, +both a direct binding to a Material, and any number of +collection-based bindings to Materials; each binding can be +generic or declared for a particular purpose, and given a specific +binding strength. It is the process of”material resolution”(see +UsdShadeMaterialBindingAPI_MaterialResolution) that examines all of +these bindings, and selects the one Material that best matches the +client’s needs. +The intent of purpose is that each gprim should be able to resolve +a Material for any given purpose, which implies it can have +differently bound materials for different purposes. There are two +special values of purpose defined in UsdShade, although the API +fully supports specifying arbitrary values for it, for the sake of +extensibility: + +UsdShadeTokens->full : to be used when the purpose of the +render is entirely to visualize the truest representation of a scene, +considering all lighting and material information, at highest +fidelity. +UsdShadeTokens->preview : to be used when the render is in +service of a goal other than a high fidelity”full”render (such as +scene manipulation, modeling, or realtime playback). Latency and speed +are generally of greater concern for preview renders, therefore +preview materials are generally designed to be”lighterweight”compared +to full materials. +A binding can also have no specific purpose at all, in which case, it +is considered to be the fallback or all-purpose binding (denoted by +the empty-valued token UsdShadeTokens->allPurpose). + +The purpose of a material binding is encoded in the name of the +binding relationship. + +In the case of a direct binding, the allPurpose binding is +represented by the relationship named “material:binding”. Special- +purpose direct bindings are represented by relationships named +“material:binding: *purpose*. A direct binding relationship must +have a single target path that points to a UsdShadeMaterial. +In the case of a collection-based binding, the allPurpose +binding is represented by a relationship +named”material:binding:collection:bindingName”, where +bindingName establishes an identity for the binding that is unique +on the prim. Attempting to establish two collection bindings of the +same name on the same prim will result in the first binding simply +being overridden. A special-purpose collection-based binding is +represented by a relationship +named”material:binding:collection:purpose:bindingName”. A +collection-based binding relationship must have exacly two targets, +one of which should be a collection-path (see ef +UsdCollectionAPI::GetCollectionPath() ) and the other should point to +a UsdShadeMaterial. In the future, we may allow a single +collection binding to target multiple collections, if we can establish +a reasonable round-tripping pattern for applications that only allow a +single collection to be associated with each Material. + +Note: Both bindingName and purpose must be non-namespaced +tokens. This allows us to know the role of a binding relationship +simply from the number of tokens in it. + +Two tokens : the fallback,”all purpose”, direct binding, +material:binding +Three tokens : a purpose-restricted, direct, fallback +binding, e.g. material:binding:preview +Four tokens : an all-purpose, collection-based binding, e.g. +material:binding:collection:metalBits +Five tokens : a purpose-restricted, collection-based binding, +e.g. material:binding:collection:full:metalBits + +A binding-strength value is used to specify whether a binding +authored on a prim should be weaker or stronger than bindings that +appear lower in namespace. We encode the binding strength with as +token-valued metadata ‘bindMaterialAs’ for future flexibility, +even though for now, there are only two possible values: +UsdShadeTokens->weakerThanDescendants and +UsdShadeTokens->strongerThanDescendants. When binding-strength is +not authored (i.e. empty) on a binding-relationship, the default +behavior matches UsdShadeTokens->weakerThanDescendants. +If a material binding relationship is a built-in property defined as +part of a typed prim’s schema, a fallback value should not be provided +for it. This is because the”material resolution”algorithm only +conisders authored properties. +Classes: + +CollectionBinding + +DirectBinding + +Methods: + +AddPrimToBindingCollection(prim, ...) +Adds the specified prim to the collection targeted by the binding relationship corresponding to given bindingName and materialPurpose . + +Apply +classmethod Apply(prim) -> MaterialBindingAPI + +Bind(material, bindingStrength, materialPurpose) +Authors a direct binding to the given material on this prim. + +CanApply +classmethod CanApply(prim, whyNot) -> bool + +CanContainPropertyName +classmethod CanContainPropertyName(name) -> bool + +ComputeBoundMaterial(bindingsCache, ...) +Computes the resolved bound material for this prim, for the given material purpose. + +ComputeBoundMaterials +classmethod ComputeBoundMaterials(prims, materialPurpose, bindingRels) -> list[Material] + +CreateMaterialBindSubset(subsetName, ...) +Creates a GeomSubset named subsetName with element type, elementType and familyName materialBind **below this prim.** + +Get +classmethod Get(stage, path) -> MaterialBindingAPI + +GetCollectionBindingRel(bindingName, ...) +Returns the collection-based material-binding relationship with the given bindingName and materialPurpose on this prim. + +GetCollectionBindingRels(materialPurpose) +Returns the list of collection-based material binding relationships on this prim for the given material purpose, materialPurpose . + +GetCollectionBindings(materialPurpose) +Returns all the collection-based bindings on this prim for the given material purpose. + +GetDirectBinding(materialPurpose) +Computes and returns the direct binding for the given material purpose on this prim. + +GetDirectBindingRel(materialPurpose) +Returns the direct material-binding relationship on this prim for the given material purpose. + +GetMaterialBindSubsets() +Returns all the existing GeomSubsets with familyName=UsdShadeTokens->materialBind below this prim. + +GetMaterialBindSubsetsFamilyType() +Returns the familyType of the family of"materialBind"GeomSubsets on this prim. + +GetMaterialBindingStrength +classmethod GetMaterialBindingStrength(bindingRel) -> str + +GetMaterialPurposes +classmethod GetMaterialPurposes() -> list[TfToken] + +GetResolvedTargetPathFromBindingRel +classmethod GetResolvedTargetPathFromBindingRel(bindingRel) -> Path + +GetSchemaAttributeNames +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] + +RemovePrimFromBindingCollection(prim, ...) +Removes the specified prim from the collection targeted by the binding relationship corresponding to given bindingName and materialPurpose . + +SetMaterialBindSubsetsFamilyType(familyType) +Author the familyType of the"materialBind"family of GeomSubsets on this prim. + +SetMaterialBindingStrength +classmethod SetMaterialBindingStrength(bindingRel, bindingStrength) -> bool + +UnbindAllBindings() +Unbinds all direct and collection-based bindings on this prim. + +UnbindCollectionBinding(bindingName, ...) +Unbinds the collection-based binding with the given bindingName , for the given materialPurpose on this prim. + +UnbindDirectBinding(materialPurpose) +Unbinds the direct binding for the given material purpose ( materialPurpose ) on this prim. + +class CollectionBinding +Methods: + +GetBindingRel + +GetCollection + +GetCollectionPath + +GetMaterial + +GetMaterialPath + +IsCollectionBindingRel + +IsValid + +GetBindingRel() + +GetCollection() + +GetCollectionPath() + +GetMaterial() + +GetMaterialPath() + +static IsCollectionBindingRel() + +IsValid() + +class DirectBinding +Methods: + +GetBindingRel + +GetMaterial + +GetMaterialPath + +GetMaterialPurpose + +GetBindingRel() + +GetMaterial() + +GetMaterialPath() + +GetMaterialPurpose() + +AddPrimToBindingCollection(prim, bindingName, materialPurpose) → bool +Adds the specified prim to the collection targeted by the binding +relationship corresponding to given bindingName and +materialPurpose . +If the collection-binding relationship doesn’t exist or if the +targeted collection already includes the prim , then this does +nothing and returns true. +If the targeted collection does not include prim (or excludes it +explicitly), then this modifies the collection by adding the prim to +it (by invoking UsdCollectionAPI::AddPrim()). + +Parameters + +prim (Prim) – +bindingName (str) – +materialPurpose (str) – + +static Apply() +classmethod Apply(prim) -> MaterialBindingAPI +Applies this single-apply API schema to the given prim . +This information is stored by adding”MaterialBindingAPI”to the token- +valued, listOp metadata apiSchemas on the prim. +A valid UsdShadeMaterialBindingAPI object is returned upon success. An +invalid (or empty) UsdShadeMaterialBindingAPI object is returned upon +failure. See UsdPrim::ApplyAPI() for conditions resulting in failure. +UsdPrim::GetAppliedSchemas() +UsdPrim::HasAPI() +UsdPrim::CanApplyAPI() +UsdPrim::ApplyAPI() +UsdPrim::RemoveAPI() + +Parameters +prim (Prim) – + +Bind(material, bindingStrength, materialPurpose) → bool +Authors a direct binding to the given material on this prim. +If bindingStrength is UsdShadeTokens->fallbackStrength, the value +UsdShadeTokens->weakerThanDescendants is authored sparsely. To stamp +out the bindingStrength value explicitly, clients can pass in +UsdShadeTokens->weakerThanDescendants or +UsdShadeTokens->strongerThanDescendants directly. +If materialPurpose is specified and isn’t equal to +UsdShadeTokens->allPurpose, the binding only applies to the specified +material purpose. +Note that UsdShadeMaterialBindingAPI is a SingleAppliedAPI schema +which when applied updates the prim definition accordingly. This +information on the prim definition is helpful in multiple queries and +more performant. Hence its recommended to call +UsdShadeMaterialBindingAPI::Apply() when Binding a material. +Returns true on success, false otherwise. + +Parameters + +material (Material) – +bindingStrength (str) – +materialPurpose (str) – + +Bind(collection, material, bindingName, bindingStrength, materialPurpose) -> bool +Authors a collection-based binding, which binds the given material +to the given collection on this prim. +bindingName establishes an identity for the binding that is unique +on the prim. Attempting to establish two collection bindings of the +same name on the same prim will result in the first binding simply +being overridden. If bindingName is empty, it is set to the base- +name of the collection being bound (which is the collection-name with +any namespaces stripped out). If there are multiple collections with +the same base-name being bound at the same prim, clients should pass +in a unique binding name per binding, in order to preserve all +bindings. The binding name used in constructing the collection-binding +relationship name shoud not contain namespaces. Hence, a coding error +is issued and no binding is authored if the provided value of +bindingName is non-empty and contains namespaces. +If bindingStrength is UsdShadeTokens->fallbackStrength, the +value UsdShadeTokens->weakerThanDescendants is authored sparsely, i.e. +only when there is an existing binding with a different +bindingStrength. To stamp out the bindingStrength value explicitly, +clients can pass in UsdShadeTokens->weakerThanDescendants or +UsdShadeTokens->strongerThanDescendants directly. +If materialPurpose is specified and isn’t equal to +UsdShadeTokens->allPurpose, the binding only applies to the specified +material purpose. +Note that UsdShadeMaterialBindingAPI is a SingleAppliedAPI schema +which when applied updates the prim definition accordingly. This +information on the prim definition is helpful in multiple queries and +more performant. Hence its recommended to call +UsdShadeMaterialBindingAPI::Apply() when Binding a material. +Returns true on success, false otherwise. + +Parameters + +collection (CollectionAPI) – +material (Material) – +bindingName (str) – +bindingStrength (str) – +materialPurpose (str) – + +static CanApply() +classmethod CanApply(prim, whyNot) -> bool +Returns true if this single-apply API schema can be applied to the +given prim . +If this schema can not be a applied to the prim, this returns false +and, if provided, populates whyNot with the reason it can not be +applied. +Note that if CanApply returns false, that does not necessarily imply +that calling Apply will fail. Callers are expected to call CanApply +before calling Apply if they want to ensure that it is valid to apply +a schema. +UsdPrim::GetAppliedSchemas() +UsdPrim::HasAPI() +UsdPrim::CanApplyAPI() +UsdPrim::ApplyAPI() +UsdPrim::RemoveAPI() + +Parameters + +prim (Prim) – +whyNot (str) – + +static CanContainPropertyName() +classmethod CanContainPropertyName(name) -> bool +Test whether a given name contains the”material:binding:”prefix. + +Parameters +name (str) – + +ComputeBoundMaterial(bindingsCache, collectionQueryCache, materialPurpose, bindingRel) → Material +Computes the resolved bound material for this prim, for the given +material purpose. +This overload of ComputeBoundMaterial makes use of the BindingsCache ( +bindingsCache ) and CollectionQueryCache ( +collectionQueryCache ) that are passed in, to avoid redundant +binding computations and computations of MembershipQuery objects for +collections. It would be beneficial to make use of these when +resolving bindings for a tree of prims. These caches are populated +lazily as more and more bindings are resolved. +When the goal is to compute the bound material for a range (or list) +of prims, it is recommended to use this version of +ComputeBoundMaterial() . Here’s how you could compute the bindings of +a range of prims efficiently in C++: +std::vector primBindings; +UsdShadeMaterialBindingAPI::BindingsCache bindingsCache; +UsdShadeMaterialBindingAPI::CollectionQueryCache collQueryCache; + +for (auto prim : UsdPrimRange(rootPrim)) { + UsdShadeMaterial boundMaterial = + UsdShadeMaterialBindingAPI(prim).ComputeBoundMaterial( + & bindingsCache, & collQueryCache); + if (boundMaterial) { + primBindings.emplace_back({prim, boundMaterial}); + } +} + +If bindingRel is not null, then it is set to the”winning”binding +relationship. +Note the resolved bound material is considered valid if the target +path of the binding relationship is a valid non-empty prim path. This +makes sure winning binding relationship and the bound material remain +consistent consistent irrespective of the presence/absence of prim at +material path. For ascenario where ComputeBoundMaterial returns a +invalid UsdShadeMaterial with a valid winning bindingRel, clients can +use the static method +UsdShadeMaterialBindingAPI::GetResolvedTargetPathFromBindingRel to get +the path of the resolved target identified by the winning bindingRel. +See Bound Material Resolution for details on the material resolution +process. +The python version of this method returns a tuple containing the bound +material and the”winning”binding relationship. + +Parameters + +bindingsCache (BindingsCache) – +collectionQueryCache (CollectionQueryCache) – +materialPurpose (str) – +bindingRel (Relationship) – + +ComputeBoundMaterial(materialPurpose, bindingRel) -> Material +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. +Computes the resolved bound material for this prim, for the given +material purpose. +This overload does not utilize cached MembershipQuery object. However, +it only computes the MembershipQuery of every collection that bound in +the ancestor chain at most once. +If bindingRel is not null, then it is set to the winning binding +relationship. +See Bound Material Resolution for details on the material resolution +process. +The python version of this method returns a tuple containing the bound +material and the”winning”binding relationship. + +Parameters + +materialPurpose (str) – +bindingRel (Relationship) – + +static ComputeBoundMaterials() +classmethod ComputeBoundMaterials(prims, materialPurpose, bindingRels) -> list[Material] +Static API for efficiently and concurrently computing the resolved +material bindings for a vector of UsdPrims, prims for the given +materialPurpose . +The size of the returned vector always matches the size of the input +vector, prims . If a prim is not bound to any material, an invalid +or empty UsdShadeMaterial is returned at the index corresponding to +it. +If the pointer bindingRels points to a valid vector, then it is +populated with the set of all”winning”binding relationships. +The python version of this method returns a tuple containing two lists +- the bound materials and the corresponding”winning”binding +relationships. + +Parameters + +prims (list[Prim]) – +materialPurpose (str) – +bindingRels (list[Relationship]) – + +CreateMaterialBindSubset(subsetName, indices, elementType) → Subset +Creates a GeomSubset named subsetName with element type, +elementType and familyName materialBind **below this prim.** +If a GeomSubset named subsetName already exists, then +its”familyName”is updated to be UsdShadeTokens->materialBind and its +indices (at default timeCode) are updated with the provided +indices value before returning. +This method forces the familyType of the”materialBind”family of +subsets to UsdGeomTokens->nonOverlapping if it’s unset or explicitly +set to UsdGeomTokens->unrestricted. +The default value elementType is UsdGeomTokens->face, as we expect +materials to be bound most often to subsets of faces on meshes. + +Parameters + +subsetName (str) – +indices (IntArray) – +elementType (str) – + +static Get() +classmethod Get(stage, path) -> MaterialBindingAPI +Return a UsdShadeMaterialBindingAPI holding the prim adhering to this +schema at path on stage . +If no prim exists at path on stage , or if the prim at that +path does not adhere to this schema, return an invalid schema object. +This is shorthand for the following: +UsdShadeMaterialBindingAPI(stage->GetPrimAtPath(path)); + +Parameters + +stage (Stage) – +path (Path) – + +GetCollectionBindingRel(bindingName, materialPurpose) → Relationship +Returns the collection-based material-binding relationship with the +given bindingName and materialPurpose on this prim. +For info on bindingName , see UsdShadeMaterialBindingAPI::Bind() . +The material purpose of the relationship that’s returned will match +the specified materialPurpose . + +Parameters + +bindingName (str) – +materialPurpose (str) – + +GetCollectionBindingRels(materialPurpose) → list[Relationship] +Returns the list of collection-based material binding relationships on +this prim for the given material purpose, materialPurpose . +The returned list of binding relationships will be in native property +order. See UsdPrim::GetPropertyOrder() , UsdPrim::SetPropertyOrder() . +Bindings that appear earlier in the property order are considered to +be stronger than the ones that come later. See rule #6 in +UsdShadeMaterialBindingAPI_MaterialResolution. + +Parameters +materialPurpose (str) – + +GetCollectionBindings(materialPurpose) → list[CollectionBinding] +Returns all the collection-based bindings on this prim for the given +material purpose. +The returned CollectionBinding objects always have the specified +materialPurpose (i.e. the all-purpose binding is not returned if a +special purpose binding is requested). +If one or more collection based bindings are to prims that are not +Materials, this does not generate an error, but the corresponding +Material(s) will be invalid (i.e. evaluate to false). +The python version of this API returns a tuple containing the vector +of CollectionBinding objects and the corresponding vector of binding +relationships. +The returned list of collection-bindings will be in native property +order of the associated binding relationships. See +UsdPrim::GetPropertyOrder() , UsdPrim::SetPropertyOrder() . Binding +relationships that come earlier in the list are considered to be +stronger than the ones that come later. See rule #6 in +UsdShadeMaterialBindingAPI_MaterialResolution. + +Parameters +materialPurpose (str) – + +GetDirectBinding(materialPurpose) → DirectBinding +Computes and returns the direct binding for the given material purpose +on this prim. +The returned binding always has the specified materialPurpose +(i.e. the all-purpose binding is not returned if a special purpose +binding is requested). +If the direct binding is to a prim that is not a Material, this does +not generate an error, but the returned Material will be invalid (i.e. +evaluate to false). + +Parameters +materialPurpose (str) – + +GetDirectBindingRel(materialPurpose) → Relationship +Returns the direct material-binding relationship on this prim for the +given material purpose. +The material purpose of the relationship that’s returned will match +the specified materialPurpose . + +Parameters +materialPurpose (str) – + +GetMaterialBindSubsets() → list[Subset] +Returns all the existing GeomSubsets with +familyName=UsdShadeTokens->materialBind below this prim. + +GetMaterialBindSubsetsFamilyType() → str +Returns the familyType of the family of”materialBind”GeomSubsets on +this prim. +By default, materialBind subsets have familyType=”nonOverlapping”, but +they can also be tagged as a”partition”, using +SetMaterialBindFaceSubsetsFamilyType(). +UsdGeomSubset::GetFamilyNameAttr + +static GetMaterialBindingStrength() +classmethod GetMaterialBindingStrength(bindingRel) -> str +Resolves the’bindMaterialAs’token-valued metadata on the given binding +relationship and returns it. +If the resolved value is empty, this returns the fallback value +UsdShadeTokens->weakerThanDescendants. +UsdShadeMaterialBindingAPI::SetMaterialBindingStrength() + +Parameters +bindingRel (Relationship) – + +static GetMaterialPurposes() +classmethod GetMaterialPurposes() -> list[TfToken] +Returns a vector of the possible values for the’material purpose’. + +static GetResolvedTargetPathFromBindingRel() +classmethod GetResolvedTargetPathFromBindingRel(bindingRel) -> Path +returns the path of the resolved target identified by bindingRel . + +Parameters +bindingRel (Relationship) – + +static GetSchemaAttributeNames() +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] +Return a vector of names of all pre-declared attributes for this +schema class and all its ancestor classes. +Does not include attributes that may be authored by custom/extended +methods of the schemas involved. + +Parameters +includeInherited (bool) – + +RemovePrimFromBindingCollection(prim, bindingName, materialPurpose) → bool +Removes the specified prim from the collection targeted by the +binding relationship corresponding to given bindingName and +materialPurpose . +If the collection-binding relationship doesn’t exist or if the +targeted collection does not include the prim , then this does +nothing and returns true. +If the targeted collection includes prim , then this modifies the +collection by removing the prim from it (by invoking +UsdCollectionAPI::RemovePrim()). This method can be used in +conjunction with the Unbind*() methods (if desired) to guarantee +that a prim has no resolved material binding. + +Parameters + +prim (Prim) – +bindingName (str) – +materialPurpose (str) – + +SetMaterialBindSubsetsFamilyType(familyType) → bool +Author the familyType of the”materialBind”family of GeomSubsets on +this prim. +The default familyType is UsdGeomTokens->nonOverlapping *. It can +be set to *UsdGeomTokens->partition to indicate that the entire +imageable prim is included in the union of all +the”materialBind”subsets. The family type should never be set to +UsdGeomTokens->unrestricted, since it is invalid for a single piece of +geometry (in this case, a subset) to be bound to more than one +material. Hence, a coding error is issued if familyType is +UsdGeomTokens->unrestricted.** +** +UsdGeomSubset::SetFamilyType** + +Parameters +familyType (str) – + +static SetMaterialBindingStrength() +classmethod SetMaterialBindingStrength(bindingRel, bindingStrength) -> bool +Sets the’bindMaterialAs’token-valued metadata on the given binding +relationship. +If bindingStrength is UsdShadeTokens->fallbackStrength, the +value UsdShadeTokens->weakerThanDescendants is authored sparsely, i.e. +only when there is a different existing bindingStrength value. To +stamp out the bindingStrength value explicitly, clients can pass in +UsdShadeTokens->weakerThanDescendants or +UsdShadeTokens->strongerThanDescendants directly. Returns true on +success, false otherwise. +UsdShadeMaterialBindingAPI::GetMaterialBindingStrength() + +Parameters + +bindingRel (Relationship) – +bindingStrength (str) – + +UnbindAllBindings() → bool +Unbinds all direct and collection-based bindings on this prim. + +UnbindCollectionBinding(bindingName, materialPurpose) → bool +Unbinds the collection-based binding with the given bindingName , +for the given materialPurpose on this prim. +It accomplishes this by blocking the targets of the associated binding +relationship in the current edit target. +If a binding was created without specifying a bindingName , then +the correct bindingName to use for unbinding is the instance name +of the targetted collection. + +Parameters + +bindingName (str) – +materialPurpose (str) – + +UnbindDirectBinding(materialPurpose) → bool +Unbinds the direct binding for the given material purpose ( +materialPurpose ) on this prim. +It accomplishes this by blocking the targets of the binding +relationship in the current edit target. + +Parameters +materialPurpose (str) – + +class pxr.UsdShade.NodeDefAPI +UsdShadeNodeDefAPI is an API schema that provides attributes for a +prim to select a corresponding Shader Node Definition (“Sdr Node”), as +well as to look up a runtime entry for that shader node in the form of +an SdrShaderNode. +UsdShadeNodeDefAPI is intended to be a pre-applied API schema for any +prim type that wants to refer to the SdrRegistry for further +implementation details about the behavior of that prim. The primary +use in UsdShade itself is as UsdShadeShader, which is a basis for +material shading networks (UsdShadeMaterial), but this is intended to +be used in other domains that also use the Sdr node mechanism. +This schema provides properties that allow a prim to identify an +external node definition, either by a direct identifier key into the +SdrRegistry (info:id), an asset to be parsed by a suitable +NdrParserPlugin (info:sourceAsset), or an inline source code that must +also be parsed (info:sourceCode); as well as a selector attribute to +determine which specifier is active (info:implementationSource). +For any described attribute Fallback Value or Allowed Values +below that are text/tokens, the actual token is published and defined +in UsdShadeTokens. So to set an attribute to the value”rightHanded”, +use UsdShadeTokens->rightHanded as the value. +Methods: + +Apply +classmethod Apply(prim) -> NodeDefAPI + +CanApply +classmethod CanApply(prim, whyNot) -> bool + +CreateIdAttr(defaultValue, writeSparsely) +See GetIdAttr() , and also Create vs Get Property Methods for when to use Get vs Create. + +CreateImplementationSourceAttr(defaultValue, ...) +See GetImplementationSourceAttr() , and also Create vs Get Property Methods for when to use Get vs Create. + +Get +classmethod Get(stage, path) -> NodeDefAPI + +GetIdAttr() +The id is an identifier for the type or purpose of the shader. + +GetImplementationSource() +Reads the value of info:implementationSource attribute and returns a token identifying the attribute that must be consulted to identify the shader's source program. + +GetImplementationSourceAttr() +Specifies the attribute that should be consulted to get the shader's implementation or its source code. + +GetSchemaAttributeNames +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] + +GetShaderId(id) +Fetches the shader's ID value from the info:id attribute, if the shader's info:implementationSource is id. + +GetShaderNodeForSourceType(sourceType) +This method attempts to ensure that there is a ShaderNode in the shader registry (i.e. + +GetSourceAsset(sourceAsset, sourceType) +Fetches the shader's source asset value for the specified sourceType value from the info: *sourceType*: sourceAsset attribute, if the shader's info:implementationSource is sourceAsset. + +GetSourceAssetSubIdentifier(subIdentifier, ...) +Fetches the shader's sub-identifier for the source asset with the specified sourceType value from the info: *sourceType*: sourceAsset:subIdentifier attribute, if the shader's info: implementationSource is sourceAsset. + +GetSourceCode(sourceCode, sourceType) +Fetches the shader's source code for the specified sourceType value by reading the info: *sourceType*: sourceCode attribute, if the shader's info:implementationSource is sourceCode. + +SetShaderId(id) +Sets the shader's ID value. + +SetSourceAsset(sourceAsset, sourceType) +Sets the shader's source-asset path value to sourceAsset for the given source type, sourceType . + +SetSourceAssetSubIdentifier(subIdentifier, ...) +Set a sub-identifier to be used with a source asset of the given source type. + +SetSourceCode(sourceCode, sourceType) +Sets the shader's source-code value to sourceCode for the given source type, sourceType . + +static Apply() +classmethod Apply(prim) -> NodeDefAPI +Applies this single-apply API schema to the given prim . +This information is stored by adding”NodeDefAPI”to the token-valued, +listOp metadata apiSchemas on the prim. +A valid UsdShadeNodeDefAPI object is returned upon success. An invalid +(or empty) UsdShadeNodeDefAPI object is returned upon failure. See +UsdPrim::ApplyAPI() for conditions resulting in failure. +UsdPrim::GetAppliedSchemas() +UsdPrim::HasAPI() +UsdPrim::CanApplyAPI() +UsdPrim::ApplyAPI() +UsdPrim::RemoveAPI() + +Parameters +prim (Prim) – + +static CanApply() +classmethod CanApply(prim, whyNot) -> bool +Returns true if this single-apply API schema can be applied to the +given prim . +If this schema can not be a applied to the prim, this returns false +and, if provided, populates whyNot with the reason it can not be +applied. +Note that if CanApply returns false, that does not necessarily imply +that calling Apply will fail. Callers are expected to call CanApply +before calling Apply if they want to ensure that it is valid to apply +a schema. +UsdPrim::GetAppliedSchemas() +UsdPrim::HasAPI() +UsdPrim::CanApplyAPI() +UsdPrim::ApplyAPI() +UsdPrim::RemoveAPI() + +Parameters + +prim (Prim) – +whyNot (str) – + +CreateIdAttr(defaultValue, writeSparsely) → Attribute +See GetIdAttr() , and also Create vs Get Property Methods for when to +use Get vs Create. +If specified, author defaultValue as the attribute’s default, +sparsely (when it makes sense to do so) if writeSparsely is +true - the default for writeSparsely is false . + +Parameters + +defaultValue (VtValue) – +writeSparsely (bool) – + +CreateImplementationSourceAttr(defaultValue, writeSparsely) → Attribute +See GetImplementationSourceAttr() , and also Create vs Get Property +Methods for when to use Get vs Create. +If specified, author defaultValue as the attribute’s default, +sparsely (when it makes sense to do so) if writeSparsely is +true - the default for writeSparsely is false . + +Parameters + +defaultValue (VtValue) – +writeSparsely (bool) – + +static Get() +classmethod Get(stage, path) -> NodeDefAPI +Return a UsdShadeNodeDefAPI holding the prim adhering to this schema +at path on stage . +If no prim exists at path on stage , or if the prim at that +path does not adhere to this schema, return an invalid schema object. +This is shorthand for the following: +UsdShadeNodeDefAPI(stage->GetPrimAtPath(path)); + +Parameters + +stage (Stage) – +path (Path) – + +GetIdAttr() → Attribute +The id is an identifier for the type or purpose of the shader. +E.g.: Texture or FractalFloat. The use of this id will depend on the +render target: some will turn it into an actual shader path, some will +use it to generate shader source code dynamically. +SetShaderId() +Declaration +uniform token info:id +C++ Type +TfToken +Usd Type +SdfValueTypeNames->Token +Variability +SdfVariabilityUniform + +GetImplementationSource() → str +Reads the value of info:implementationSource attribute and returns a +token identifying the attribute that must be consulted to identify the +shader’s source program. +This returns + +id, to indicate that the”info:id”attribute must be consulted. +sourceAsset to indicate that the asset- +valued”info:{sourceType}:sourceAsset”attribute associated with the +desired sourceType should be consulted to locate the asset with +the shader’s source. +sourceCode to indicate that the string- +valued”info:{sourceType}:sourceCode”attribute associated with the +desired sourceType should be read to get shader’s source. + +This issues a warning and returns id if the +info:implementationSource attribute has an invalid value. +{sourceType} above is a place holder for a token that identifies the +type of shader source or its implementation. For example: osl, glslfx, +riCpp etc. This allows a shader to specify different sourceAsset (or +sourceCode) values for different sourceTypes. The sourceType tokens +usually correspond to the sourceType value of the NdrParserPlugin +that’s used to parse the shader source (NdrParserPlugin::SourceType). +When sourceType is empty, the corresponding sourceAsset or sourceCode +is considered to be”universal”(or fallback), which is represented by +the empty-valued token UsdShadeTokens->universalSourceType. When the +sourceAsset (or sourceCode) corresponding to a specific, requested +sourceType is unavailable, the universal sourceAsset (or sourceCode) +is returned by GetSourceAsset (and GetSourceCode} API, if present. +GetShaderId() +GetSourceAsset() +GetSourceCode() + +GetImplementationSourceAttr() → Attribute +Specifies the attribute that should be consulted to get the shader’s +implementation or its source code. + +If set to”id”, the”info:id”attribute’s value is used to determine +the shader source from the shader registry. +If set to”sourceAsset”, the resolved value of +the”info:sourceAsset”attribute corresponding to the desired +implementation (or source-type) is used to locate the shader source. A +source asset file may also specify multiple shader definitions, so +there is an optional attribute”info:sourceAsset:subIdentifier”whose +value should be used to indicate a particular shader definition from a +source asset file. +If set to”sourceCode”, the value of”info:sourceCode”attribute +corresponding to the desired implementation (or source type) is used +as the shader source. + +Declaration +uniform token info:implementationSource ="id" +C++ Type +TfToken +Usd Type +SdfValueTypeNames->Token +Variability +SdfVariabilityUniform +Allowed Values +id, sourceAsset, sourceCode + +static GetSchemaAttributeNames() +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] +Return a vector of names of all pre-declared attributes for this +schema class and all its ancestor classes. +Does not include attributes that may be authored by custom/extended +methods of the schemas involved. + +Parameters +includeInherited (bool) – + +GetShaderId(id) → bool +Fetches the shader’s ID value from the info:id attribute, if the +shader’s info:implementationSource is id. +Returns true if the shader’s implementation source is id and +the value was fetched properly into id . Returns false otherwise. +GetImplementationSource() + +Parameters +id (str) – + +GetShaderNodeForSourceType(sourceType) → ShaderNode +This method attempts to ensure that there is a ShaderNode in the +shader registry (i.e. +SdrRegistry) representing this shader for the given sourceType . +It may return a null pointer if none could be found or created. + +Parameters +sourceType (str) – + +GetSourceAsset(sourceAsset, sourceType) → bool +Fetches the shader’s source asset value for the specified +sourceType value from the info: *sourceType*: sourceAsset +attribute, if the shader’s info:implementationSource is +sourceAsset. +If the sourceAsset attribute corresponding to the requested +sourceType isn’t present on the shader, then the universal +fallback sourceAsset attribute, i.e. info:sourceAsset is +consulted, if present, to get the source asset path. +Returns true if the shader’s implementation source is +sourceAsset and the source asset path value was fetched +successfully into sourceAsset . Returns false otherwise. +GetImplementationSource() + +Parameters + +sourceAsset (AssetPath) – +sourceType (str) – + +GetSourceAssetSubIdentifier(subIdentifier, sourceType) → bool +Fetches the shader’s sub-identifier for the source asset with the +specified sourceType value from the info: *sourceType*: +sourceAsset:subIdentifier attribute, if the shader’s info: +implementationSource is sourceAsset. +If the subIdentifier attribute corresponding to the requested +sourceType isn’t present on the shader, then the universal +fallback sub-identifier attribute, i.e. info:sourceAsset: +subIdentifier is consulted, if present, to get the sub-identifier +name. +Returns true if the shader’s implementation source is +sourceAsset and the sub-identifier for the given source type was +fetched successfully into subIdentifier . Returns false otherwise. + +Parameters + +subIdentifier (str) – +sourceType (str) – + +GetSourceCode(sourceCode, sourceType) → bool +Fetches the shader’s source code for the specified sourceType +value by reading the info: *sourceType*: sourceCode attribute, if +the shader’s info:implementationSource is sourceCode. +If the sourceCode attribute corresponding to the requested +sourceType isn’t present on the shader, then the universal or +fallback sourceCode attribute (i.e. info:sourceCode) is consulted, +if present, to get the source code. +Returns true if the shader’s implementation source is +sourceCode and the source code string was fetched successfully +into sourceCode . Returns false otherwise. +GetImplementationSource() + +Parameters + +sourceCode (str) – +sourceType (str) – + +SetShaderId(id) → bool +Sets the shader’s ID value. +This also sets the info:implementationSource attribute on the shader +to UsdShadeTokens->id, if the existing value is different. + +Parameters +id (str) – + +SetSourceAsset(sourceAsset, sourceType) → bool +Sets the shader’s source-asset path value to sourceAsset for the +given source type, sourceType . +This also sets the info:implementationSource attribute on the shader +to UsdShadeTokens->sourceAsset. + +Parameters + +sourceAsset (AssetPath) – +sourceType (str) – + +SetSourceAssetSubIdentifier(subIdentifier, sourceType) → bool +Set a sub-identifier to be used with a source asset of the given +source type. +This sets the info: *sourceType*: sourceAsset:subIdentifier. +This also sets the info:implementationSource attribute on the shader +to UsdShadeTokens->sourceAsset + +Parameters + +subIdentifier (str) – +sourceType (str) – + +SetSourceCode(sourceCode, sourceType) → bool +Sets the shader’s source-code value to sourceCode for the given +source type, sourceType . +This also sets the info:implementationSource attribute on the shader +to UsdShadeTokens->sourceCode. + +Parameters + +sourceCode (str) – +sourceType (str) – + +class pxr.UsdShade.NodeGraph +A node-graph is a container for shading nodes, as well as other node- +graphs. It has a public input interface and provides a list of public +outputs. +Node Graph Interfaces +One of the most important functions of a node-graph is to host +the”interface”with which clients of already-built shading networks +will interact. Please see Interface Inputs for a detailed explanation +of what the interface provides, and how to construct and use it, to +effectively share/instance shader networks. +Node Graph Outputs +These behave like outputs on a shader and are typically connected to +an output on a shader inside the node-graph. +Methods: + +ComputeInterfaceInputConsumersMap(...) +Walks the namespace subtree below the node-graph and computes a map containing the list of all inputs on the node-graph and the associated vector of consumers of their values. + +ComputeOutputSource(outputName, sourceName, ...) +Deprecated + +ConnectableAPI() +Contructs and returns a UsdShadeConnectableAPI object with this node- graph. + +CreateInput(name, typeName) +Create an Input which can either have a value or can be connected. + +CreateOutput(name, typeName) +Create an output which can either have a value or can be connected. + +Define +classmethod Define(stage, path) -> NodeGraph + +Get +classmethod Get(stage, path) -> NodeGraph + +GetInput(name) +Return the requested input if it exists. + +GetInputs(onlyAuthored) +Returns all inputs present on the node-graph. + +GetInterfaceInputs() +Returns all the"Interface Inputs"of the node-graph. + +GetOutput(name) +Return the requested output if it exists. + +GetOutputs(onlyAuthored) +Outputs are represented by attributes in the"outputs:"namespace. + +GetSchemaAttributeNames +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] + +ComputeInterfaceInputConsumersMap(computeTransitiveConsumers) → InterfaceInputConsumersMap +Walks the namespace subtree below the node-graph and computes a map +containing the list of all inputs on the node-graph and the associated +vector of consumers of their values. +The consumers can be inputs on shaders within the node-graph or on +nested node-graphs). +If computeTransitiveConsumers is true, then value consumers +belonging to node-graphs are resolved transitively to compute the +transitive mapping from inputs on the node-graph to inputs on shaders +inside the material. Note that inputs on node-graphs that don’t have +value consumers will continue to be included in the result. +This API is provided for use by DCC’s that want to present node-graph +interface / shader connections in the opposite direction than they are +encoded in USD. + +Parameters +computeTransitiveConsumers (bool) – + +ComputeOutputSource(outputName, sourceName, sourceType) → Shader +Deprecated +in favor of GetValueProducingAttributes on UsdShadeOutput Resolves the +connection source of the requested output, identified by +outputName to a shader output. +sourceName is an output parameter that is set to the name of the +resolved output, if the node-graph output is connected to a valid +shader source. +sourceType is an output parameter that is set to the type of the +resolved output, if the node-graph output is connected to a valid +shader source. +Returns a valid shader object if the specified output exists and is +connected to one. Return an empty shader object otherwise. The python +version of this method returns a tuple containing three elements (the +source shader, sourceName, sourceType). + +Parameters + +outputName (str) – +sourceName (str) – +sourceType (AttributeType) – + +ConnectableAPI() → ConnectableAPI +Contructs and returns a UsdShadeConnectableAPI object with this node- +graph. +Note that most tasks can be accomplished without explicitly +constructing a UsdShadeConnectable API, since connection-related API +such as UsdShadeConnectableAPI::ConnectToSource() are static methods, +and UsdShadeNodeGraph will auto-convert to a UsdShadeConnectableAPI +when passed to functions that want to act generically on a connectable +UsdShadeConnectableAPI object. + +CreateInput(name, typeName) → Input +Create an Input which can either have a value or can be connected. +The attribute representing the input is created in +the”inputs:”namespace. + +Parameters + +name (str) – +typeName (ValueTypeName) – + +CreateOutput(name, typeName) → Output +Create an output which can either have a value or can be connected. +The attribute representing the output is created in +the”outputs:”namespace. + +Parameters + +name (str) – +typeName (ValueTypeName) – + +static Define() +classmethod Define(stage, path) -> NodeGraph +Attempt to ensure a UsdPrim adhering to this schema at path is +defined (according to UsdPrim::IsDefined() ) on this stage. +If a prim adhering to this schema at path is already defined on +this stage, return that prim. Otherwise author an SdfPrimSpec with +specifier == SdfSpecifierDef and this schema’s prim type name for +the prim at path at the current EditTarget. Author SdfPrimSpec s +with specifier == SdfSpecifierDef and empty typeName at the +current EditTarget for any nonexistent, or existing but not Defined +ancestors. +The given path must be an absolute prim path that does not contain +any variant selections. +If it is impossible to author any of the necessary PrimSpecs, (for +example, in case path cannot map to the current UsdEditTarget ‘s +namespace) issue an error and return an invalid UsdPrim. +Note that this method may return a defined prim whose typeName does +not specify this schema class, in case a stronger typeName opinion +overrides the opinion at the current EditTarget. + +Parameters + +stage (Stage) – +path (Path) – + +static Get() +classmethod Get(stage, path) -> NodeGraph +Return a UsdShadeNodeGraph holding the prim adhering to this schema at +path on stage . +If no prim exists at path on stage , or if the prim at that +path does not adhere to this schema, return an invalid schema object. +This is shorthand for the following: +UsdShadeNodeGraph(stage->GetPrimAtPath(path)); + +Parameters + +stage (Stage) – +path (Path) – + +GetInput(name) → Input +Return the requested input if it exists. + +Parameters +name (str) – + +GetInputs(onlyAuthored) → list[Input] +Returns all inputs present on the node-graph. +These are represented by attributes in the”inputs:”namespace. If +onlyAuthored is true (the default), then only return authored +attributes; otherwise, this also returns un-authored builtins. + +Parameters +onlyAuthored (bool) – + +GetInterfaceInputs() → list[Input] +Returns all the”Interface Inputs”of the node-graph. +This is the same as GetInputs() , but is provided as a convenience, to +allow clients to distinguish between inputs on shaders vs. interface- +inputs on node-graphs. + +GetOutput(name) → Output +Return the requested output if it exists. + +Parameters +name (str) – + +GetOutputs(onlyAuthored) → list[Output] +Outputs are represented by attributes in the”outputs:”namespace. +If onlyAuthored is true (the default), then only return authored +attributes; otherwise, this also returns un-authored builtins. + +Parameters +onlyAuthored (bool) – + +static GetSchemaAttributeNames() +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] +Return a vector of names of all pre-declared attributes for this +schema class and all its ancestor classes. +Does not include attributes that may be authored by custom/extended +methods of the schemas involved. + +Parameters +includeInherited (bool) – + +class pxr.UsdShade.Output +This class encapsulates a shader or node-graph output, which is a +connectable attribute representing a typed, externally computed value. +Methods: + +CanConnect(source) +Determines whether this Output can be connected to the given source attribute, which can be an input or an output. + +ClearSdrMetadata() +Clears any"sdrMetadata"value authored on the Output in the current EditTarget. + +ClearSdrMetadataByKey(key) +Clears the entry corresponding to the given key in the"sdrMetadata"dictionary authored in the current EditTarget. + +ClearSource() +Deprecated + +ClearSources() +Clears sources for this Output in the current UsdEditTarget. + +ConnectToSource(source, mod) +Authors a connection for this Output. + +DisconnectSource(sourceAttr) +Disconnect source for this Output. + +GetAttr() +Explicit UsdAttribute extractor. + +GetBaseName() +Returns the name of the output. + +GetConnectedSource(source, sourceName, ...) +Deprecated + +GetConnectedSources(invalidSourcePaths) +Finds the valid sources of connections for the Output. + +GetFullName() +Get the name of the attribute associated with the output. + +GetPrim() +Get the prim that the output belongs to. + +GetRawConnectedSourcePaths(sourcePaths) +Deprecated + +GetRenderType() +Return this output's specialized renderType, or an empty token if none was authored. + +GetSdrMetadata() +Returns this Output's composed"sdrMetadata"dictionary as a NdrTokenMap. + +GetSdrMetadataByKey(key) +Returns the value corresponding to key in the composed sdrMetadata dictionary. + +GetTypeName() +Get the"scene description"value type name of the attribute associated with the output. + +GetValueProducingAttributes(shaderOutputsOnly) +Find what is connected to this Output recursively. + +HasConnectedSource() +Returns true if and only if this Output is currently connected to a valid (defined) source. + +HasRenderType() +Return true if a renderType has been specified for this output. + +HasSdrMetadata() +Returns true if the Output has a non-empty composed"sdrMetadata"dictionary value. + +HasSdrMetadataByKey(key) +Returns true if there is a value corresponding to the given key in the composed"sdrMetadata"dictionary. + +IsOutput +classmethod IsOutput(attr) -> bool + +IsSourceConnectionFromBaseMaterial() +Returns true if the connection to this Output's source, as returned by GetConnectedSource() , is authored across a specializes arc, which is used to denote a base material. + +Set(value, time) +Set a value for the output. + +SetConnectedSources(sourceInfos) +Connects this Output to the given sources, sourceInfos . + +SetRenderType(renderType) +Specify an alternative, renderer-specific type to use when emitting/translating this output, rather than translating based on its GetTypeName() + +SetSdrMetadata(sdrMetadata) +Authors the given sdrMetadata value on this Output at the current EditTarget. + +SetSdrMetadataByKey(key, value) +Sets the value corresponding to key to the given string value , in the Output's"sdrMetadata"dictionary at the current EditTarget. + +CanConnect(source) → bool +Determines whether this Output can be connected to the given source +attribute, which can be an input or an output. +An output is considered to be connectable only if it belongs to a +node-graph. Shader outputs are not connectable. +UsdShadeConnectableAPI::CanConnect + +Parameters +source (Attribute) – + +CanConnect(sourceInput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +sourceInput (Input) – + +CanConnect(sourceOutput) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters +sourceOutput (Output) – + +ClearSdrMetadata() → None +Clears any”sdrMetadata”value authored on the Output in the current +EditTarget. + +ClearSdrMetadataByKey(key) → None +Clears the entry corresponding to the given key in +the”sdrMetadata”dictionary authored in the current EditTarget. + +Parameters +key (str) – + +ClearSource() → bool +Deprecated + +ClearSources() → bool +Clears sources for this Output in the current UsdEditTarget. +Most of the time, what you probably want is DisconnectSource() rather +than this function. +UsdShadeConnectableAPI::ClearSources + +ConnectToSource(source, mod) → bool +Authors a connection for this Output. +source is a struct that describes the upstream source attribute +with all the information necessary to make a connection. See the +documentation for UsdShadeConnectionSourceInfo. mod describes the +operation that should be applied to the list of connections. By +default the new connection will replace any existing connections, but +it can add to the list of connections to represent multiple input +connections. +true if a connection was created successfully. false if +shadingAttr or source is invalid. +This method does not verify the connectability of the shading +attribute to the source. Clients must invoke CanConnect() themselves +to ensure compatibility. +The source shading attribute is created if it doesn’t exist already. +UsdShadeConnectableAPI::ConnectToSource + +Parameters + +source (ConnectionSourceInfo) – +mod (ConnectionModification) – + +ConnectToSource(source, sourceName, sourceType, typeName) -> bool +Deprecated +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – +typeName (ValueTypeName) – + +ConnectToSource(sourcePath) -> bool +Authors a connection for this Output to the source at the given path. +UsdShadeConnectableAPI::ConnectToSource + +Parameters +sourcePath (Path) – + +ConnectToSource(sourceInput) -> bool +Connects this Output to the given input, sourceInput . +UsdShadeConnectableAPI::ConnectToSource + +Parameters +sourceInput (Input) – + +ConnectToSource(sourceOutput) -> bool +Connects this Output to the given output, sourceOutput . +UsdShadeConnectableAPI::ConnectToSource + +Parameters +sourceOutput (Output) – + +DisconnectSource(sourceAttr) → bool +Disconnect source for this Output. +If sourceAttr is valid, only a connection to the specified +attribute is disconnected, otherwise all connections are removed. +UsdShadeConnectableAPI::DisconnectSource + +Parameters +sourceAttr (Attribute) – + +GetAttr() → Attribute +Explicit UsdAttribute extractor. + +GetBaseName() → str +Returns the name of the output. +We call this the base name since it strips off the”outputs:”namespace +prefix from the attribute name, and returns it. + +GetConnectedSource(source, sourceName, sourceType) → bool +Deprecated +Please use GetConnectedSources instead + +Parameters + +source (ConnectableAPI) – +sourceName (str) – +sourceType (AttributeType) – + +GetConnectedSources(invalidSourcePaths) → list[SourceInfo] +Finds the valid sources of connections for the Output. +invalidSourcePaths is an optional output parameter to collect the +invalid source paths that have not been reported in the returned +vector. +Returns a vector of UsdShadeConnectionSourceInfo structs with +information about each upsteam attribute. If the vector is empty, +there have been no valid connections. +A valid connection requires the existence of the source attribute and +also requires that the source prim is UsdShadeConnectableAPI +compatible. +The python wrapping returns a tuple with the valid connections first, +followed by the invalid source paths. +UsdShadeConnectableAPI::GetConnectedSources + +Parameters +invalidSourcePaths (list[SdfPath]) – + +GetFullName() → str +Get the name of the attribute associated with the output. + +GetPrim() → Prim +Get the prim that the output belongs to. + +GetRawConnectedSourcePaths(sourcePaths) → bool +Deprecated +Returns the”raw”(authored) connected source paths for this Output. +UsdShadeConnectableAPI::GetRawConnectedSourcePaths + +Parameters +sourcePaths (list[SdfPath]) – + +GetRenderType() → str +Return this output’s specialized renderType, or an empty token if none +was authored. +SetRenderType() + +GetSdrMetadata() → NdrTokenMap +Returns this Output’s composed”sdrMetadata”dictionary as a +NdrTokenMap. + +GetSdrMetadataByKey(key) → str +Returns the value corresponding to key in the composed +sdrMetadata dictionary. + +Parameters +key (str) – + +GetTypeName() → ValueTypeName +Get the”scene description”value type name of the attribute associated +with the output. + +GetValueProducingAttributes(shaderOutputsOnly) → list[UsdShadeAttribute] +Find what is connected to this Output recursively. +UsdShadeUtils::GetValueProducingAttributes + +Parameters +shaderOutputsOnly (bool) – + +HasConnectedSource() → bool +Returns true if and only if this Output is currently connected to a +valid (defined) source. +UsdShadeConnectableAPI::HasConnectedSource + +HasRenderType() → bool +Return true if a renderType has been specified for this output. +SetRenderType() + +HasSdrMetadata() → bool +Returns true if the Output has a non-empty +composed”sdrMetadata”dictionary value. + +HasSdrMetadataByKey(key) → bool +Returns true if there is a value corresponding to the given key in +the composed”sdrMetadata”dictionary. + +Parameters +key (str) – + +static IsOutput() +classmethod IsOutput(attr) -> bool +Test whether a given UsdAttribute represents a valid Output, which +implies that creating a UsdShadeOutput from the attribute will +succeed. +Success implies that attr.IsDefined() is true. + +Parameters +attr (Attribute) – + +IsSourceConnectionFromBaseMaterial() → bool +Returns true if the connection to this Output’s source, as returned by +GetConnectedSource() , is authored across a specializes arc, which is +used to denote a base material. +UsdShadeConnectableAPI::IsSourceConnectionFromBaseMaterial + +Set(value, time) → bool +Set a value for the output. +It’s unusual to be setting a value on an output since it represents an +externally computed value. The Set API is provided here just for the +sake of completeness and uniformity with other property schema. + +Parameters + +value (VtValue) – +time (TimeCode) – + +Set(value, time) -> bool +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. +Set the attribute value of the Output at time . + +Parameters + +value (T) – +time (TimeCode) – + +SetConnectedSources(sourceInfos) → bool +Connects this Output to the given sources, sourceInfos . +UsdShadeConnectableAPI::SetConnectedSources + +Parameters +sourceInfos (list[ConnectionSourceInfo]) – + +SetRenderType(renderType) → bool +Specify an alternative, renderer-specific type to use when +emitting/translating this output, rather than translating based on its +GetTypeName() +For example, we set the renderType to”struct”for outputs that are of +renderman custom struct types. +true on success + +Parameters +renderType (str) – + +SetSdrMetadata(sdrMetadata) → None +Authors the given sdrMetadata value on this Output at the current +EditTarget. + +Parameters +sdrMetadata (NdrTokenMap) – + +SetSdrMetadataByKey(key, value) → None +Sets the value corresponding to key to the given string value +, in the Output’s”sdrMetadata”dictionary at the current EditTarget. + +Parameters + +key (str) – +value (str) – + +class pxr.UsdShade.Shader +Base class for all USD shaders. Shaders are the building blocks of +shading networks. While UsdShadeShader objects are not target +specific, each renderer or application target may derive its own +renderer-specific shader object types from this base, if needed. +Objects of this class generally represent a single shading object, +whether it exists in the target renderer or not. For example, a +texture, a fractal, or a mix node. +The UsdShadeNodeDefAPI provides attributes to uniquely identify the +type of this node. The id resolution into a renderable shader target +type of this node. The id resolution into a renderable shader target +is deferred to the consuming application. +The purpose of representing them in Usd is two-fold: + +To represent, via”connections”the topology of the shading network +that must be reconstructed in the renderer. Facilities for authoring +and manipulating connections are encapsulated in the API schema +UsdShadeConnectableAPI. +To present a (partial or full) interface of typed input +parameters whose values can be set and overridden in Usd, to be +provided later at render-time as parameter values to the actual render +shader objects. Shader input parameters are encapsulated in the +property schema UsdShadeInput. + +Methods: + +ClearSdrMetadata() +Clears any"sdrMetadata"value authored on the shader in the current EditTarget. + +ClearSdrMetadataByKey(key) +Clears the entry corresponding to the given key in the"sdrMetadata"dictionary authored in the current EditTarget. + +ConnectableAPI() +Contructs and returns a UsdShadeConnectableAPI object with this shader. + +CreateIdAttr(defaultValue, writeSparsely) +Forwards to UsdShadeNodeDefAPI(prim). + +CreateImplementationSourceAttr(defaultValue, ...) +Forwards to UsdShadeNodeDefAPI(prim). + +CreateInput(name, typeName) +Create an input which can either have a value or can be connected. + +CreateOutput(name, typeName) +Create an output which can either have a value or can be connected. + +Define +classmethod Define(stage, path) -> Shader + +Get +classmethod Get(stage, path) -> Shader + +GetIdAttr() +Forwards to UsdShadeNodeDefAPI(prim). + +GetImplementationSource() +Forwards to UsdShadeNodeDefAPI(prim). + +GetImplementationSourceAttr() +Forwards to UsdShadeNodeDefAPI(prim). + +GetInput(name) +Return the requested input if it exists. + +GetInputs(onlyAuthored) +Inputs are represented by attributes in the"inputs:"namespace. + +GetOutput(name) +Return the requested output if it exists. + +GetOutputs(onlyAuthored) +Outputs are represented by attributes in the"outputs:"namespace. + +GetSchemaAttributeNames +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] + +GetSdrMetadata() +Returns this shader's composed"sdrMetadata"dictionary as a NdrTokenMap. + +GetSdrMetadataByKey(key) +Returns the value corresponding to key in the composed sdrMetadata dictionary. + +GetShaderId(id) +Forwards to UsdShadeNodeDefAPI(prim). + +GetShaderNodeForSourceType(sourceType) +Forwards to UsdShadeNodeDefAPI(prim). + +GetSourceAsset(sourceAsset, sourceType) +Forwards to UsdShadeNodeDefAPI(prim). + +GetSourceAssetSubIdentifier(subIdentifier, ...) +Forwards to UsdShadeNodeDefAPI(prim). + +GetSourceCode(sourceCode, sourceType) +Forwards to UsdShadeNodeDefAPI(prim). + +HasSdrMetadata() +Returns true if the shader has a non-empty composed"sdrMetadata"dictionary value. + +HasSdrMetadataByKey(key) +Returns true if there is a value corresponding to the given key in the composed"sdrMetadata"dictionary. + +SetSdrMetadata(sdrMetadata) +Authors the given sdrMetadata on this shader at the current EditTarget. + +SetSdrMetadataByKey(key, value) +Sets the value corresponding to key to the given string value , in the shader's"sdrMetadata"dictionary at the current EditTarget. + +SetShaderId(id) +Forwards to UsdShadeNodeDefAPI(prim). + +SetSourceAsset(sourceAsset, sourceType) +Forwards to UsdShadeNodeDefAPI(prim). + +SetSourceAssetSubIdentifier(subIdentifier, ...) +Forwards to UsdShadeNodeDefAPI(prim). + +SetSourceCode(sourceCode, sourceType) +Forwards to UsdShadeNodeDefAPI(prim). + +ClearSdrMetadata() → None +Clears any”sdrMetadata”value authored on the shader in the current +EditTarget. + +ClearSdrMetadataByKey(key) → None +Clears the entry corresponding to the given key in +the”sdrMetadata”dictionary authored in the current EditTarget. + +Parameters +key (str) – + +ConnectableAPI() → ConnectableAPI +Contructs and returns a UsdShadeConnectableAPI object with this +shader. +Note that most tasks can be accomplished without explicitly +constructing a UsdShadeConnectable API, since connection-related API +such as UsdShadeConnectableAPI::ConnectToSource() are static methods, +and UsdShadeShader will auto-convert to a UsdShadeConnectableAPI when +passed to functions that want to act generically on a connectable +UsdShadeConnectableAPI object. + +CreateIdAttr(defaultValue, writeSparsely) → Attribute +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +defaultValue (VtValue) – +writeSparsely (bool) – + +CreateImplementationSourceAttr(defaultValue, writeSparsely) → Attribute +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +defaultValue (VtValue) – +writeSparsely (bool) – + +CreateInput(name, typeName) → Input +Create an input which can either have a value or can be connected. +The attribute representing the input is created in +the”inputs:”namespace. Inputs on both shaders and node-graphs are +connectable. + +Parameters + +name (str) – +typeName (ValueTypeName) – + +CreateOutput(name, typeName) → Output +Create an output which can either have a value or can be connected. +The attribute representing the output is created in +the”outputs:”namespace. Outputs on a shader cannot be connected, as +their value is assumed to be computed externally. + +Parameters + +name (str) – +typeName (ValueTypeName) – + +static Define() +classmethod Define(stage, path) -> Shader +Attempt to ensure a UsdPrim adhering to this schema at path is +defined (according to UsdPrim::IsDefined() ) on this stage. +If a prim adhering to this schema at path is already defined on +this stage, return that prim. Otherwise author an SdfPrimSpec with +specifier == SdfSpecifierDef and this schema’s prim type name for +the prim at path at the current EditTarget. Author SdfPrimSpec s +with specifier == SdfSpecifierDef and empty typeName at the +current EditTarget for any nonexistent, or existing but not Defined +ancestors. +The given path must be an absolute prim path that does not contain +any variant selections. +If it is impossible to author any of the necessary PrimSpecs, (for +example, in case path cannot map to the current UsdEditTarget ‘s +namespace) issue an error and return an invalid UsdPrim. +Note that this method may return a defined prim whose typeName does +not specify this schema class, in case a stronger typeName opinion +overrides the opinion at the current EditTarget. + +Parameters + +stage (Stage) – +path (Path) – + +static Get() +classmethod Get(stage, path) -> Shader +Return a UsdShadeShader holding the prim adhering to this schema at +path on stage . +If no prim exists at path on stage , or if the prim at that +path does not adhere to this schema, return an invalid schema object. +This is shorthand for the following: +UsdShadeShader(stage->GetPrimAtPath(path)); + +Parameters + +stage (Stage) – +path (Path) – + +GetIdAttr() → Attribute +Forwards to UsdShadeNodeDefAPI(prim). + +GetImplementationSource() → str +Forwards to UsdShadeNodeDefAPI(prim). + +GetImplementationSourceAttr() → Attribute +Forwards to UsdShadeNodeDefAPI(prim). + +GetInput(name) → Input +Return the requested input if it exists. + +Parameters +name (str) – + +GetInputs(onlyAuthored) → list[Input] +Inputs are represented by attributes in the”inputs:”namespace. +If onlyAuthored is true (the default), then only return authored +attributes; otherwise, this also returns un-authored builtins. + +Parameters +onlyAuthored (bool) – + +GetOutput(name) → Output +Return the requested output if it exists. + +Parameters +name (str) – + +GetOutputs(onlyAuthored) → list[Output] +Outputs are represented by attributes in the”outputs:”namespace. +If onlyAuthored is true (the default), then only return authored +attributes; otherwise, this also returns un-authored builtins. + +Parameters +onlyAuthored (bool) – + +static GetSchemaAttributeNames() +classmethod GetSchemaAttributeNames(includeInherited) -> list[TfToken] +Return a vector of names of all pre-declared attributes for this +schema class and all its ancestor classes. +Does not include attributes that may be authored by custom/extended +methods of the schemas involved. + +Parameters +includeInherited (bool) – + +GetSdrMetadata() → NdrTokenMap +Returns this shader’s composed”sdrMetadata”dictionary as a +NdrTokenMap. + +GetSdrMetadataByKey(key) → str +Returns the value corresponding to key in the composed +sdrMetadata dictionary. + +Parameters +key (str) – + +GetShaderId(id) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters +id (str) – + +GetShaderNodeForSourceType(sourceType) → ShaderNode +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters +sourceType (str) – + +GetSourceAsset(sourceAsset, sourceType) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +sourceAsset (AssetPath) – +sourceType (str) – + +GetSourceAssetSubIdentifier(subIdentifier, sourceType) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +subIdentifier (str) – +sourceType (str) – + +GetSourceCode(sourceCode, sourceType) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +sourceCode (str) – +sourceType (str) – + +HasSdrMetadata() → bool +Returns true if the shader has a non-empty +composed”sdrMetadata”dictionary value. + +HasSdrMetadataByKey(key) → bool +Returns true if there is a value corresponding to the given key in +the composed”sdrMetadata”dictionary. + +Parameters +key (str) – + +SetSdrMetadata(sdrMetadata) → None +Authors the given sdrMetadata on this shader at the current +EditTarget. + +Parameters +sdrMetadata (NdrTokenMap) – + +SetSdrMetadataByKey(key, value) → None +Sets the value corresponding to key to the given string value +, in the shader’s”sdrMetadata”dictionary at the current EditTarget. + +Parameters + +key (str) – +value (str) – + +SetShaderId(id) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters +id (str) – + +SetSourceAsset(sourceAsset, sourceType) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +sourceAsset (AssetPath) – +sourceType (str) – + +SetSourceAssetSubIdentifier(subIdentifier, sourceType) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +subIdentifier (str) ��� +sourceType (str) – + +SetSourceCode(sourceCode, sourceType) → bool +Forwards to UsdShadeNodeDefAPI(prim). + +Parameters + +sourceCode (str) – +sourceType (str) – + +class pxr.UsdShade.ShaderDefParserPlugin +Parses shader definitions represented using USD scene description +using the schemas provided by UsdShade. +Methods: + +GetDiscoveryTypes() +Returns the types of nodes that this plugin can parse. + +GetSourceType() +Returns the source type that this parser operates on. + +Parse(discoveryResult) +Takes the specified NdrNodeDiscoveryResult instance, which was a result of the discovery process, and generates a new NdrNode . + +GetDiscoveryTypes() → NdrTokenVec +Returns the types of nodes that this plugin can parse. +“Type”here is the discovery type (in the case of files, this will +probably be the file extension, but in other systems will be data that +can be determined during discovery). This type should only be used to +match up a NdrNodeDiscoveryResult to its parser plugin; this value +is not exposed in the node’s API. + +GetSourceType() → str +Returns the source type that this parser operates on. +A source type is the most general type for a node. The parser plugin +is responsible for parsing all discovery results that have the types +declared under GetDiscoveryTypes() , and those types are +collectively identified as one”source type”. + +Parse(discoveryResult) → NdrNodeUnique +Takes the specified NdrNodeDiscoveryResult instance, which was a +result of the discovery process, and generates a new NdrNode . +The node’s name, source type, and family must match. + +Parameters +discoveryResult (NodeDiscoveryResult) – + +class pxr.UsdShade.ShaderDefUtils +This class contains a set of utility functions used for populating the +shader registry with shaders definitions specified using UsdShade +schemas. +Methods: + +GetNodeDiscoveryResults +classmethod GetNodeDiscoveryResults(shaderDef, sourceUri) -> NdrNodeDiscoveryResultVec + +GetPrimvarNamesMetadataString +classmethod GetPrimvarNamesMetadataString(metadata, shaderDef) -> str + +GetShaderProperties +classmethod GetShaderProperties(shaderDef) -> NdrPropertyUniquePtrVec + +static GetNodeDiscoveryResults() +classmethod GetNodeDiscoveryResults(shaderDef, sourceUri) -> NdrNodeDiscoveryResultVec +Returns the list of NdrNodeDiscoveryResult objects that must be added +to the shader registry for the given shader shaderDef , assuming +it is found in a shader definition file found by an Ndr discovery +plugin. +To enable the shaderDef parser to find and parse this shader, +sourceUri should have the resolved path to the usd file containing +this shader prim. + +Parameters + +shaderDef (Shader) – +sourceUri (str) – + +static GetPrimvarNamesMetadataString() +classmethod GetPrimvarNamesMetadataString(metadata, shaderDef) -> str +Collects all the names of valid primvar inputs of the given +metadata and the given shaderDef and returns the string used +to represent them in SdrShaderNode metadata. + +Parameters + +metadata (NdrTokenMap) – +shaderDef (ConnectableAPI) – + +static GetShaderProperties() +classmethod GetShaderProperties(shaderDef) -> NdrPropertyUniquePtrVec +Gets all input and output properties of the given shaderDef and +translates them into NdrProperties that can be used as the properties +for an SdrShaderNode. + +Parameters +shaderDef (ConnectableAPI) – + +class pxr.UsdShade.Tokens +Attributes: + +allPurpose + +bindMaterialAs + +coordSys + +displacement + +fallbackStrength + +full + +id + +infoId + +infoImplementationSource + +inputs + +interfaceOnly + +materialBind + +materialBinding + +materialBindingCollection + +materialVariant + +outputs + +outputsDisplacement + +outputsSurface + +outputsVolume + +preview + +sdrMetadata + +sourceAsset + +sourceCode + +strongerThanDescendants + +subIdentifier + +surface + +universalRenderContext + +universalSourceType + +volume + +weakerThanDescendants + +allPurpose = '' + +bindMaterialAs = 'bindMaterialAs' + +coordSys = 'coordSys:' + +displacement = 'displacement' + +fallbackStrength = 'fallbackStrength' + +full = 'full' + +id = 'id' + +infoId = 'info:id' + +infoImplementationSource = 'info:implementationSource' + +inputs = 'inputs:' + +interfaceOnly = 'interfaceOnly' + +materialBind = 'materialBind' + +materialBinding = 'material:binding' + +materialBindingCollection = 'material:binding:collection' + +materialVariant = 'materialVariant' + +outputs = 'outputs:' + +outputsDisplacement = 'outputs:displacement' + +outputsSurface = 'outputs:surface' + +outputsVolume = 'outputs:volume' + +preview = 'preview' + +sdrMetadata = 'sdrMetadata' + +sourceAsset = 'sourceAsset' + +sourceCode = 'sourceCode' + +strongerThanDescendants = 'strongerThanDescendants' + +subIdentifier = 'subIdentifier' + +surface = 'surface' + +universalRenderContext = '' + +universalSourceType = '' + +volume = 'volume' + +weakerThanDescendants = 'weakerThanDescendants' + +class pxr.UsdShade.Utils +This class contains a set of utility functions used when authoring and +querying shading networks. +Methods: + +GetBaseNameAndType +classmethod GetBaseNameAndType(fullName) -> tuple[str, AttributeType] + +GetConnectedSourcePath +classmethod GetConnectedSourcePath(srcInfo) -> Path + +GetFullName +classmethod GetFullName(baseName, type) -> str + +GetPrefixForAttributeType +classmethod GetPrefixForAttributeType(sourceType) -> str + +GetType +classmethod GetType(fullName) -> AttributeType + +GetValueProducingAttributes +classmethod GetValueProducingAttributes(input, shaderOutputsOnly) -> list[UsdShadeAttribute] + +static GetBaseNameAndType() +classmethod GetBaseNameAndType(fullName) -> tuple[str, AttributeType] +Given the full name of a shading attribute, returns it’s base name and +shading attribute type. + +Parameters +fullName (str) – + +static GetConnectedSourcePath() +classmethod GetConnectedSourcePath(srcInfo) -> Path +For a valid UsdShadeConnectionSourceInfo, return the complete path to +the source property; otherwise the empty path. + +Parameters +srcInfo (ConnectionSourceInfo) – + +static GetFullName() +classmethod GetFullName(baseName, type) -> str +Returns the full shading attribute name given the basename and the +shading attribute type. +baseName is the name of the input or output on the shading node. +type is the UsdShadeAttributeType of the shading attribute. + +Parameters + +baseName (str) – +type (AttributeType) – + +static GetPrefixForAttributeType() +classmethod GetPrefixForAttributeType(sourceType) -> str +Returns the namespace prefix of the USD attribute associated with the +given shading attribute type. + +Parameters +sourceType (AttributeType) – + +static GetType() +classmethod GetType(fullName) -> AttributeType +Given the full name of a shading attribute, returns its shading +attribute type. + +Parameters +fullName (str) – + +static GetValueProducingAttributes() +classmethod GetValueProducingAttributes(input, shaderOutputsOnly) -> list[UsdShadeAttribute] +Find what is connected to an Input or Output recursively. +GetValueProducingAttributes implements the UsdShade connectivity rules +described in Connection Resolution Utilities. +When tracing connections within networks that contain containers like +UsdShadeNodeGraph nodes, the actual output(s) or value(s) at the end +of an input or output might be multiple connections removed. The +methods below resolves this across multiple physical connections. +An UsdShadeInput is getting its value from one of these sources: + +If the input is not connected the UsdAttribute for this input is +returned, but only if it has an authored value. The input attribute +itself carries the value for this input. +If the input is connected we follow the connection(s) until we +reach a valid output of a UsdShadeShader node or if we reach a valid +UsdShadeInput attribute of a UsdShadeNodeGraph or UsdShadeMaterial +that has an authored value. + +An UsdShadeOutput on a container can get its value from the same type +of sources as a UsdShadeInput on either a UsdShadeShader or +UsdShadeNodeGraph. Outputs on non-containers (UsdShadeShaders) cannot +be connected. +This function returns a vector of UsdAttributes. The vector is empty +if no valid attribute was found. The type of each attribute can be +determined with the UsdShadeUtils::GetType function. +If shaderOutputsOnly is true, it will only report attributes that +are outputs of non-containers (UsdShadeShaders). This is a bit faster +and what is need when determining the connections for Material +terminals. +This will return the last attribute along the connection chain that +has an authored value, which might not be the last attribute in the +chain itself. +When the network contains multi-connections, this function can return +multiple attributes for a single input or output. The list of +attributes is build by a depth-first search, following the underlying +connection paths in order. The list can contain both UsdShadeOutput +and UsdShadeInput attributes. It is up to the caller to decide how to +process such a mixture. + +Parameters + +input (Input) – +shaderOutputsOnly (bool) – + +GetValueProducingAttributes(output, shaderOutputsOnly) -> list[UsdShadeAttribute] +This is an overloaded member function, provided for convenience. It +differs from the above function only in what argument(s) it accepts. + +Parameters + +output (Output) – +shaderOutputsOnly (bool) – + +© Copyright 2019-2023, NVIDIA. + Last updated on Nov 14, 2023. + + +