| CameraUtil module — pxr-usd-api 105.1 documentation | |
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| CameraUtil module | |
| # CameraUtil module | |
| Summary: Camera Utilities | |
| Camera utilities. | |
| Classes: | |
| ConformWindowPolicy | |
| Framing | |
| Framing information. | |
| ScreenWindowParameters | |
| Given a camera object, compute parameters suitable for setting up RenderMan. | |
| class pxr.CameraUtil.ConformWindowPolicy | |
| Methods: | |
| GetValueFromName | |
| Attributes: | |
| allValues | |
| static GetValueFromName() | |
| allValues = (CameraUtil.MatchVertically, CameraUtil.MatchHorizontally, CameraUtil.Fit, CameraUtil.Crop, CameraUtil.DontConform) | |
| class pxr.CameraUtil.Framing | |
| Framing information. That is information determining how the filmback | |
| plane of a camera maps to the pixels of the rendered image | |
| (displayWindow together with pixelAspectRatio and window policy) and | |
| what pixels of the image will be filled by the renderer (dataWindow). | |
| The concepts of displayWindow and dataWindow are similar to the ones | |
| in OpenEXR, including that the x- and y-axis of the coordinate system | |
| point left and down, respectively. | |
| In fact, these windows mean the same here and in OpenEXR if the | |
| displayWindow has the same aspect ratio (when accounting for the | |
| pixelAspectRatio) as the filmback plane of the camera has (that is the | |
| ratio of the horizontalAperture to verticalAperture of, e.g., Usd’s | |
| Camera or GfCamera). | |
| In particular, overscan can be achieved by making the dataWindow | |
| larger than the displayWindow. | |
| If the aspect ratios differ, a window policy is applied to the | |
| displayWindow to determine how the pixels correspond to the filmback | |
| plane. One such window policy is to take the largest rect that fits | |
| (centered) into the displayWindow and has the camera’s aspect ratio. | |
| For example, if the displayWindow and dataWindow are the same and both | |
| have an aspect ratio smaller than the camera, the image is created by | |
| enlarging the camera frustum slightly in the bottom and top direction. | |
| When using the AOVs, the render buffer size is determined | |
| independently from the framing info. However, the dataWindow is | |
| supposed to be contained in the render buffer rect (in particular, the | |
| dataWindow cannot contain pixels withs negative coordinates - this | |
| restriction does not apply if, e.g., hdPrman circumvents AOVs and | |
| writes directly to EXR). In other words, unlike in OpenEXR, the rect | |
| of pixels for which we allocate storage can differ from the rect the | |
| renderer fills with data (dataWindow). | |
| For example, an application can set the render buffer size to match | |
| the widget size but use a dataWindow and displayWindow that only fills | |
| the render buffer horizontally to have slates at the top and bottom. | |
| Methods: | |
| ApplyToProjectionMatrix(projectionMatrix, ...) | |
| Given the projectionMatrix computed from a camera, applies the framing. | |
| IsValid() | |
| Is display and data window non-empty. | |
| Attributes: | |
| dataWindow | |
| displayWindow | |
| pixelAspectRatio | |
| ApplyToProjectionMatrix(projectionMatrix, windowPolicy) → Matrix4d | |
| Given the projectionMatrix computed from a camera, applies the | |
| framing. | |
| To obtain a correct result, a rasterizer needs to use the resulting | |
| projection matrix and set the viewport to the data window. | |
| Parameters | |
| projectionMatrix (Matrix4d) – | |
| windowPolicy (ConformWindowPolicy) – | |
| IsValid() → bool | |
| Is display and data window non-empty. | |
| property dataWindow | |
| property displayWindow | |
| property pixelAspectRatio | |
| class pxr.CameraUtil.ScreenWindowParameters | |
| Given a camera object, compute parameters suitable for setting up | |
| RenderMan. | |
| Attributes: | |
| fieldOfView | |
| float | |
| screenWindow | |
| Vec4d | |
| zFacingViewMatrix | |
| Matrix4d | |
| property fieldOfView | |
| float | |
| The field of view. | |
| More precisely, the full angle perspective field of view (in degrees) | |
| between screen space coordinates (-1,0) and (1,0). Give these | |
| parameters to RiProjection as parameter after”perspective”. | |
| Type | |
| type | |
| property screenWindow | |
| Vec4d | |
| The vector (left, right, bottom, top) defining the rectangle in the | |
| image plane. | |
| Give these parameters to RiScreenWindow. | |
| Type | |
| type | |
| property zFacingViewMatrix | |
| Matrix4d | |
| Returns the inverse of the transform for a camera that is y-Up and | |
| z-facing (vs the OpenGL camera that is (-z)-facing). | |
| Write this transform with RiConcatTransform before RiWorldBegin. | |
| Type | |
| type | |
| © Copyright 2019-2023, NVIDIA. | |
| Last updated on Nov 14, 2023. | |