Recommendations:

Start a complete new Blender file with just the default cube.

go to quick effects -> quick liquid

start the animation -> looks great, right?

so you should try to keep the settings there in your file and tweak only one effect at a time to see what happens if you do that. -> or watch tons of tutorial videos

Now to your file:
to improve it you can do...

decrease resolution to 64 or 128 when you are still changing things, if you render you increase this to 256 if you like, else it takes too long and your computer will slow down

for me it looks like you "wildly" changed some settings just to get better results - without knowing what happens. e.g.

of course you can change these values (which i personally never did and i made nice looking water simulations without it), but if you increase it that hight, i just don't wanna know how long your render time for your simulation was...1 week? ;)
So put it down to the default values 4 and 1 ...and wow...your computer and your simulation is fast again

put on all border collisions -> else you got these weird results where just "some" water is on the floor which does not look realistic.

check liquid and don't change default settings

you got this: https://youtu.be/QAH1ljMFkEA

turn on spray, foam, bubbles

most important: Do the render in cycles. Only in cycles water looks really good and realistic. But change to cycles after you did all your settings because this also slows down your computer massively.

quick result of cycles render (bad resolution):

bit higher resolution (128)

Best recommendation: Don't use mantaflow.
Use Flip Fluids. I know -  you have to pay for it.
I know it is "kind of" advertising although i do not get anything from them and i don't have any relationship to the FlipFluid - addon creators.
It is just an amazing add-on which makes fluids look a lot better and - even more important - it is so much faster!!!
Here is a result of your simulation which i just did with a few clicks with FlipFluids....deleted your background, used a HDRI and ...you won't believe it ...rendered in EEVEE:
result:

aaaaand.....NOOOOOW....Cycles:

Remember: These are JUST the default settings of FlipFluids. I just assigned default materials (which are part of FlipFluids) and checked 2 checkmarks (so you can see foam + spray)


Create Nullschool Earth flowlines over displacement map

Not the most elegant solution but if you're only interested in a static image, you could use the wind map images as textures and UV unwrap the surface onto it.

Worst case scenario...you could try texture painting all the lines. Don't recommend that though, especially if you need it to be accurate.


Blender has the concept of:

Scene: Reference Objects
Objects: Reference Object Data (Mesh, Armature, Lamp. etc)

This is needed so you can (for example) have many instances of the same mesh, which saves memory and allows you to edit without having to manually update copies.

Here is the script modified to work as expected.

import bpy

arm = bpy.data.armatures.new("My Rig")

# create an object
obj = bpy.data.objects.new("My Object", arm)

bpy.context.scene.objects.link(obj)


From your screenshot you have your Vector input of the texture set to Default - this will be using a UV Map to orient the textures on your faces. In order to maps your texture over the whole mesh you either need to change the UV map (search for online tutorials for UV Unwrapping - it can be quite a simple or complicated process, depending on your needs and situation) or switch to a Vector setting that does not use your UV map - such as Generated.

I your case, Generated would seem to be the best option since you want the texture projected over the whole mesh from above - so change Vector to Generated. However, I also note from your screenshot that you have your Mapping set to 'Normal' - this can produce unexpected results (I presume this was the result of you trying to adjust your mapping) - so change it to Texture. You should then adjust the Scale and Rotation to orient the image on the mesh how you desire.


If you neglect air drag and other forces, basic mechanics tells you that there is no net torque due to the weight of the object.

Edit:
An example can be this: Imagine a point mass m attached via a massless bar to a point mass 2m. Assume that the bara is 1 meter long. Then the center of mass will be 1/3 meters from the heavier mass.

Now the gravitational force acting on the two masses is mg and 2mg, respectively.

The torque due to gravity around the center of mass from the left mass is mg*(2/3 meters), where 2/3 meters is the distance from the mass to the center of gravity. This torque tries to rotate the bar counter clockwise. Now the torque from the gravity force acting on the heaver mass is 2mg*(1/3 meters) = mg*(2/3 meters), but this torque tries to rotate the bar clockwise. Hence they two torques exactly cancels and there will be no rotation.

This can be proven also in the general case which is done in most beginners university courses on classical mechanics.


Is there a way to make rigid body interact with softbody physics?

Normally, soft bodies react to the presence of rigid bodies - providing those rigid bodies have Collision enabled - but the opposite does not occur; ie, the rigid body will not react to the presence of the soft body. This will result in the rigid body 'pushing through' the soft body :

In order to have the rigid body react to the soft body, the soft body must be made to be part of the rigid body world. This can be achieved by adding Rigid Body physics to the Soft Body as well as it being part of the soft body world.

To achieve this, enable Rigid Body in the Physics panel and set the Type as 'Passive' so that the Rigid Body simulation doesn't directly affect the soft body mesh (we'll leave the soft body engine to deal with that). Also, set it to be 'Animated'. In Rigid Body Collisions set the Shape to 'Mesh' and enable 'Deforming' since the mesh will be deforming during the animation.

The rigid body should now interact with the soft body :

Blend file included


Whats the difference between entering units and scaling the model at the end

The result should be the same if you scale your mesh in edit mode. However if you scale the whole object in object mode your object will behave differently when used with particles or in physics simulations. The particles and the forces on the object will be scaled as well. To avoid that problem you can apply the object-mode scale to the mesh by pressing [Ctrl+A] and selecting "Scale".


How to input location of selected Vertex using keyboard only

SHIFT + S and U Cursor to Center
SHIFT + S and T Selection to Cursor
G 1.5 Tab - 1 Tab 1.2 Enter

First step can be skipped when the 3D cursor is already at the center.


How can I make both sides of this mesh bright in material mode?

Every face has a normal- a direction that shows where "outside" is. By this I mean that when multiple faces are joined into an object, it tells blender that the rest of the space is outside and inside the object is inside. Blender shows the inside portion darker so you know  where your normals are facing. Unreal engine will make backside normals invisible, so I would suggest a solidify modifier with a very thin thickness. The wing will remain very thin, but not have any normal issues.


Python - How to Add a Text Field to the UI?

With a PropertyGroup and a PointerProperty you can register all your properties in the scene. They are then accessible by panels or operators under the name you've chosen.

The StringProperty allows you to set the subtype to FILE_PATH which creates a text field with a file selector. Once clicked this triggers Blender's file browser and the user can select a file. The path to the file is then stored in the property.

import bpy

class WorthGroupToolsSettings(bpy.types.PropertyGroup):
    file_path: bpy.props.StringProperty(name="File path",
                                        description="Some elaborate description",
                                        default="",
                                        maxlen=1024,
                                        subtype="FILE_PATH")

class WORTHGROUPTOOLS_PT_panel(bpy.types.Panel):
    bl_label = "WorthGroup Tools Panel"
    bl_category = "WorthGroup Tools Addon"
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"

    def draw(self, context):
        layout = self.layout
        row = layout.row()

        worth_group_tools = context.scene.worth_group_tools
        row.prop(worth_group_tools, "file_path")

classes = (WorthGroupToolsSettings,
           WORTHGROUPTOOLS_PT_panel)

def register():
    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.Scene.worth_group_tools = bpy.props.PointerProperty(type=WorthGroupToolsSettings)

def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
    del bpy.types.Scene.worth_group_tools

if __name__ == "__main__":
    register()


Wringing a torus around the circumference of its major radius

you can use a cylinder with array and curve modifier :

apply the array modifier and Unwrap the cylinder then you can get the result :


Can I permanently change some default settings like inset size, remove doubles threshold, new mesh size?

Try to look in User Preferences, in Input tab. There is 2 different ways to do what.

First if your command called right from key-building. In this case you don't need to edit any python code, just go in Input tab, find command and here you can set any default settings as you like:

For example, I changed segments count. And after changing press Save user settings.

Second than your command called from menu, like W -> Remove doubles. You can also create a new shortcut and edit this settings like I explained before:

But of course it will affects only on new keybinding. So how to change default settings in menu? This time also go in Input tab, find command Call Menu that calls from keybinding (in case of Remove doubles it will be  W ):

And we interested in Name of menu (in our case it is "VIEW3D_MT_edit_mesh_specials")

This is what can search in files, and find menu like this:

class VIEW3D_MT_edit_mesh_specials(Menu):
    bl_label = "Specials"

    def draw(self, context):
        layout = self.layout

        layout.operator_context = 'INVOKE_REGION_WIN'

        layout.operator("mesh.subdivide", text="Subdivide").smoothness = 0.0
        layout.operator("mesh.subdivide", text="Subdivide Smooth").smoothness = 1.0

        layout.separator()

        layout.operator("mesh.merge", text="Merge...")
        layout.operator("mesh.remove_doubles")

        layout.separator()

        layout.operator("mesh.hide", text="Hide").unselected = False
        layout.operator("mesh.reveal", text="Reveal")
        layout.operator("mesh.select_all", text="Select Inverse").action = 'INVERT'

        layout.separator()

        layout.operator("mesh.flip_normals")
        layout.operator("mesh.vertices_smooth", text="Smooth")
        layout.operator("mesh.vertices_smooth_laplacian", text="Laplacian Smooth")

        layout.separator()

        layout.operator("mesh.inset")
        layout.operator("mesh.bevel", text="Bevel")
        layout.operator("mesh.bridge_edge_loops")

        layout.separator()

        layout.operator("mesh.faces_shade_smooth")
        layout.operator("mesh.faces_shade_flat")

        layout.separator()

        layout.operator("mesh.blend_from_shape")
        layout.operator("mesh.shape_propagate_to_all")
        layout.operator("mesh.shortest_path_select")
        layout.operator("mesh.sort_elements")
        layout.operator("mesh.symmetrize")
        layout.operator("mesh.symmetry_snap")

I found this file here: /usr/share/blender/2.79/scripts/startup/bl_ui/space_view3d.py

This is a menu, that called from Call Menu("VIEW3D_MT_edit_mesh_specials"). Here you can add some default parameters.


How can I have a light that casts no shadows?

It is possible if you're using lamps, not objects. Simply remove the check for "Cast Shadows" under the lamp material settings.


I was interested in this so did a little research.

A blender save works by directly copying the scene data from memory to disk. This makes the save fast since there is no need for a 'conversion' stage.

This means that any change to how that data is in memory will result in the same change when in a blend file. This could be trivial changes like the order of variables in a list.

read this for more details: http://archive.blender.org/development/architecture/blender-file-format/

"Blend-files can be different when stored on different hardware platforms or Blender releases. There is no effort taken to make blend-files binary the same."

Basically it means that hashing the file cannot be used to check for content changes.

R


Is there any way to replicate/recreate Levels effect in Blender Shading Nodes?

You can get the same functionality with the Color Ramp node.

Add > Converter > Color Ramp

And because the Color Ramp node uses 0-1 value range, just multiply your value by 1 / 255.
Like this:

You can technically also do this with RGB curves, they're just a different tool for doing the same thing.


Fluid simulation is choppy with animated obstacle descending on Z axis [video included]

That's not an error; that's simply Blender telling you that your fluid it too low res. Generally, I would say, "up the Final Resolution: for a smoother result," but that won't help that much in your case (150 should be plenty for most anything).

However, in this case, the issue is that your Domain is HUGE!!! The Domain should be exactly that; a cube that encompasses anywhere your fluid might travel and NOTHING ELSE! So if you scale your domain cube from Img 1 (where it currently is) to Img 2 (what I am suggesting), your resolution (being relative to the size of the Domain) will "increase."

Img 1; how you have it:

Img 2; what I'm recommending:

Notice how it only encompasses where the water will be. Lastly, consider the following image, which shows how your fluid will bake after the modification (so much more concentration!).

I only let it bake the first frame, because baking will now take longer:

Here is a .blend file with the modifications:


You can try Plane deformed by Curve modifier plus Mirror modifier

It is quite tricky to work with curve for me. But in this case just add Curve, switch type to 2D (under Curve Properties), rotate 90°on X, in edit mode shape curve as you need. In object mode rotate on Z axis to let curve peel from cornet. Before you add paper a Curve modifier move curve object origin to paper's left top corner. Animate curve's Location.


Two operators with the same button, it's possible?

Check Text Editor Templates: Operator Simple and Operator Modal

Imagine the modal operator has bl_idname = "object.some_generic_modal". In the execute function of your other (non modal) operator you could make a direct operator call:

def execute(self, context):
    # your stuff

    # call the other operator
    bpy.ops.object.some_generic_modal()

    return {'FINISHED'}

However, to avoid the separation and extra boilerplate, you might want to stick your one-off code in the invoke of the modal operator and call that directly instead.

To clarify: with the term one-off code I meant the code which just needs to be executed once, prior to the continuous modal operator.


Controlling the "strength" of cycles' Bump node

Height input is where you plug in the texture. Distance input is the "height" of the tallest bump in blender units. Strength input is an overall scale of the height map.

It's not normally useful to use strength, unless you want to plug the same bump map into different shaders, and some have the same features yet less bump height.


You could fake it with 3 additional ortho cameras layered in the VSE with scale transform effects arranged in a quad display. It renders super quick.


Why can I see the camera gizmo in the 3D View but not the actual camera itself?

What you are seeing is the camera's gizmo, which only shows up when selecting the camera object.

To see the camera wire shape, enable Extras under Objects in the 3D Views Overlay options.

Make sure, camera visibility is on.


If I understand correctly you would basically do
def locations_to_image(objects, image_name='Locations'):
    im = bpy.data.images.new(image_name, len(objects), 1)
    i = 0
    for ob in objects:
        im.pixels[i:i+3] = xyz_to_rgb(ob.matrix_world.translation)
        i += 4
    return im

def xyz_to_rgb(xyz):
    # Replace with however you want locations encoded.
    # This is just an example.
    bb_max = 50  # bounding box size
    return [(v + bb_max)/(2*bb_max) for v in xyz]

Edit to match your specifications.
PS. RGBA components are always in the range [0,1], so you'll need to encode them somehow.


How do I join a many-faced mesh to a mesh with fewer faces?

You can use Bridge tool.

Select the two loops you want to connect;
Press W, choose Bridge Edge Loops in the popup menu. More options for Bridge tool can be found in F6 menu.

P.S. However, such topology may not benefit Surface Subdivision. So, it's recommended to have even subdivision level for both cup and handle. Suggested workflow would be:


The error on your file is that you set film exposure to 0, making everything... black. It's like taking a photograph with the lights off (or with the lens cap on).

Set it back to one!


How to create mesh collider for a blender model

If i understand you correctly, just go to physics tab and apply collision to walls. Or make a secondary box around it and give that collision. This is for blender related stuff. If you are going to export it you need to dig around youtube for a tut.


Blender weight paint, brush doesn't work properly on the mesh it barely affects the object

I tried to duplicate your video to no similar results, but It looks like is had to do with some setting you must have changed. On the left hand side check the dropdown menu for stroke and curve and check those settings, Stroke should be on space, and curve should look like its going top left to bottom right in a slope. If that doesnt work check the options tab on the left and make sure restrict is not checked on and neither is the x mirror or topology mirror.

If all else fails, under the file tab all the way up top just select "load factory settings" and that should resolve your issue. And if that fails then maybe it was a bug in the version you're using which is very old, you should update to the latest stable build which is 2.79


Set Render/Camera resolution to Render Border coordinates

For perspective camera's you can use this. Original code from https://github.com/ChameleonScales/Camera-Cropper-Splitter just cleaned up a bit.

It uses the shift property of the camera to match the original camera image. For some cases this is useful, but other cases it ain't. Then you really need to move the camera.

scene = bpy.data.scenes['Scene']
render = scene.render
camera = scene.camera

orig_res_x = render.resolution_x
orig_res_y = render.resolution_y

border_width = render.border_max_x-render.border_min_x
border_height = render.border_max_y-render.border_min_y
border_left = render.border_max_x+render.border_min_x
border_top = render.border_max_y+render.border_min_y
border_res_x = orig_res_x*border_width
border_res_y = orig_res_y*border_height

# ▼ Focal length change ▼
if (orig_res_x>orig_res_y):
    if border_res_x > border_res_y:
        camera.data.lens /= border_width
    else:
        camera.data.lens *= orig_res_x/border_res_y
else:
    if border_res_x > border_res_y:
        camera.data.lens *= orig_res_y/border_res_x
    else :
        camera.data.lens /= border_width

# ▼ Resolution change ▼
render.resolution_x = round(border_res_x)
render.resolution_y = round(border_res_y)

# ▼ Shift X ▼
if border_res_x>border_res_y:
    camera.data.shift_x = (0.5 * (border_top - 1)) / border_width
else :
    camera.data.shift_x = (0.5 * border_res_x * (border_left - 1))/(border_res_y * border_width)

# ▼ Shift Y ▼
if border_res_x>border_res_y:
    camera.data.shift_y = (0.5 * border_res_y * (border_left - 1))/(border_res_x * border_height)
else :
    camera.data.shift_y = (0.5 * (border_top - 1)) / border_height


Is it possible to render an object just with the normal map?

A normal map will allow to simulate high poly details on a low poly mesh (using light) but won't change the shape of it. You won't be able to remove the visibility of the topology on borders with good result. You can try a fresnel or layer weight node to mix a transparent but this will make holes. This could work on a volume but not on a surface shader.

All you can really do is adding a subsurf to add some topo and smooth the borders.


Your file is 380 MB heavy.  One part is that you have high poly objects with 2 UV maps for each object. That's about 150 MB. You can delete the UV maps to save space. There are also Custom Split Normals Data, about 20 MB. Then, it's still 215 MB big, but I'm not sure why Blender still needs that many bytes...?
Why it doesn't render
As already mentioned you have a few high poly objects in your scene. Each of these objects has something like 257,000 vertices, 607,000 edges, 350,000 faces - and they have a Subdivision Surface modifier, Viewport level: 0, Render level: 1. That's the problem.
If you render this, the modifier kicks in and adds some geometry... 1.2 million vertices, 2.4 million edges, 1.2 million faces for one object. This is multiplied by the number of objects and ... good night ;-)
Solution: Remove the modifiers and it will render fine.
To decrease the render time you can use the default 128 samples, tick [X] Adaptive Sampling, and use the denoiser in the compositor.
Also, these objects in the background can be rather low-poly. 5k or 10k vertices with a bump/normal map should do the trick. No need for 257k vertices.

128 samples, AA, denoiser node, 20 minutes render time (CPU), 1.5GB mem peak


If you have the same problem: Unzip, rename the folder without any dots (-> . <-) in it and insert it to the other addons manually


How to change mesh using driver like cgcookie cookieFlexRig?

The flex rig doesn't change the mesh, every hair mesh is in place at all times, the visibility is changed by using a mask modifier.

For each hair object, add a mask modifier, then add a driver for the invert option and set the driver calculation so that when a certain value is set the invert is the right way for each object.

A driver is a python expression that determines the value of the property being driven. In the case of controlling the mask modifier, the result should be a True or False value that inverts the mask effect. Drivers can be edited in the driver context of the graph editor.

The flexrig uses each number to "view" a different mesh object, the easy way to determine which is active is to test if a custom property is equal to the chosen number for each item. For example choice == 1 will be True when the custom property is set to 1. A custom property can be added to an object in the custom properties panel which is found in the object properties.

The driver panel looks a little different in 2.78 but it isn't hard to find the same settings - you choose single property and select the object that has the controlling property then enter the property name as if it was a dictionary key in python ["good"] into the path property, then you use the driver variable name in the scripted expression choice == 1


How to to do something before the blender game engine ends with a script

You can use an app event handler for this.

An event handler is a function (known as a "callback") that is launched when the event is triggered. You can append a custom function of your own to blender's event handlers, and it will be launched when these events are fired.

Conveniently, there's such an event for the end of the game engine (bpy.app.handlers.game_post).

import bpy

def execute_after_game( scene ):
    print( "GAME OVER!!" )

bpy.app.handlers.game_post.append( execute_after_game )

This example will add a function that prints "GAME OVER!!" to the terminal after the game is finished.


Probably you accidently missclicked when you wanted to change the pivot center. To the Right of that Button is a Button with a sideways arrow. It locks scaling and rotation and enables you to only change the positions of your objects while scaling or rotating.


How to make every single part of a complex geometry thinner?

Here are two ways you might be able to go about doing this, though they aren't going to provide you perfect results. Both of these techniques involve moving all faces in along their normals.
Option 1
In edit mode, select everything and hit ALT+S, then slowly draw your mouse down to shrink. You may wish to select the Offset Even checkbox in the little settings box.
Option 2
Add a displace modifier to your mesh. Leave the Midlevel at 0.5, and set the strength to 0.0. Then, slowly draw the strength into the negative numbers, which will shrink the mesh. The exact number will depend heavily on the scale of your mesh, and the degree to which you need it thinned.


Is there a way to duplicate a particle system onto a seperate mesh without using python?

Assuming the meshes are stacked in the same space:
First, copy the particle-related vertex groups to the other mesh.
Then, disconnect the particle system.
Select the new mesh, then select the one with groom.
Use copy to selected.
Reconnect the hair on the new mesh.
Should be all good. You may have to re-assign the vertex groups in the particle settings.
Best of luck :)


Create a particle with sphere object wherever you want in that liquid.
Set the liquid material to objects of that particle.
Flip normals of the sphere objects so that the inside of them will look like air.
These are my bubbles:


Position all selected vertices to the same place

Just found an answer from: http://blenderartists.org/forum/showthread.php?167457-Transform-multiple-vertices-flatten-snap-to

  There are two methods that I usually use

  select the vertices and press S Z 0 to put all the vertices in the same z-position, then move then set the 'Median Z'
  value in the transform properties.
  put the cursor in the wanted z-position, select the wanted vertices and set pivot to 3d cursor, then press  S Z 0


Custom Chain Breaks When Animated no matter what

I looked at your file and made out some problems.

Scale was not applied. For any kind of simulation, you would want your scale values to be 1, 1, 1, so after you scaled an object in object mode, hit CtrlA and choose 'scale' to apply it.
The objects were very large. In the scene tab choose a unit system (metric or imperial) to get an idea of the overall scale of your objects. Once I got them ready for simulation (step 3), they were falling very slow, because they had to travel several meters.
Keep your topology clean. Something went quite wrong with your objects, the topology is completely messed up. It also is very dense, that caused your long simulation times. (The numbers of verts are for the whole scene)

The collision margin was way too high. That caused the links to "jump off" as soon, as the simulation started.

What I couldn't fix is the jittering. To make it work somehow, I dialed down the gravity influence of the rigid body world, but that cannot be the solution. Could anyone take a second look at the files and explain, why the jittering is happening?
Also: the solver somehow has problems with the uppermost hook. I removed the rigid body collision from that one and placed some cylinders. Whenever you can, I would recommend to use the collision primitives in the rigid body settings. That is unfortunately not possible for your animation, because the objects intersect with eachother.

Here is the (partially) fixed .blend:

I hope this brings you a bit closer to your goal.


It might take a LITTLE extra work, but why don't you just:

select only the front faces
orient the view so you're looking directly at it -- i.e. View > front (Numpad 1)
From the unwrap options choose "Project from view" (in ortho mode)

This will give you as "flat" an unwrap as possible for just the faces you selected. Then, you can repeat these steps for the remaining five different views (back, left, right, top, bottom). As you do each side, you'll notice that only the UVs for the selected faces will be set -- so after each round, you may have to scale/rotate/translate and put them roughly in the position of the desired final layout. (For example, since you want it to be hinged at the top, when you do the back faces, you'll have to rotate the UVs 180 degrees clockwise and position them above the front faces.)

Once you get the scale and position for each side as close to one another as possible, you can select pairs of UVs (I use "B" so that I can box-select) and "W" to weld them together.

There might be a faster/better way to do it, but that's all I got.

Hope this helps.


Resetting camera after camera collision (BGE)

Here's the answer;

Add an empty, slightly behind the player, and put the ray on that, set the ray distance to however long you wan it to be, and turn on true level triggering.

you will need to change the code a very small amount:

from bge import logic

def collision(cont):

own = cont.owner
scene = logic.getCurrentScene()
target = scene.objects['Camera.001']
ray = cont.sensors['Ray']

if ray.positive:
    target.worldPosition = ray.hitPosition

and viola! mow the camera is added to a position based on the empties ray! if the ray is obstructed, the camera moves to the closest position!


How to keep vertices from snapping to to wrong-side of mesh when retopologizing?

You did not check "project onto self" in the snapping tab. Try that out and see if it helped.


How can I bake a rigid body simulation in 2.8?

It's in the Properties Panel > Scene > Rigid Body World > Cache


It looks like you have an odd geometry (ie: it has a lot of faces with different amount of edges). But there are some other things that can lead to this.

First, make sure you have auto smooth turned on. This can be found in the data section of the properties panel in the normal tab. See this post for more information.

The other thing that could be causing it has to do with the actual geometry. It's a little hard to describe and I'm not sure this will actually fix your problem but it's important to keep in mind. Basically, you can set an object to have smooth shading to make it look smoother on the surface, but that won't fix it around the edges.


How to apply Matcap materials for sculpting in Blender 2.71?

Note also that you must be in "Solid" view mode to see the matcap option under the N menu. This seems obvious to me now, but I've been all over the internet trying to find out why I don't see the Matcap option everyone else has. :)

-C


Create a custom operator for renaming input socket in compositor

In case you haven't worked it out by now:

import bpy
import os
filepath=bpy.context.scene.render.filepath#Get absolute render path
absolutepath=bpy.path.abspath(filepath)
path=os.path.normpath(absolutepath)#Split it
parts=path.split(os.sep)
parentpath=os.sep.join(parts[:-2])
def rename(context):#Set the path for all file output nodes
    for scene in bpy.data.scenes:
        if scene.node_tree:
            for node in scene.node_tree.nodes:
                if node.type=='OUTPUT_FILE':
                    link0=node.inputs[0].links[0]#Gets the link from the input
                    socket_name=link0.from_socket.name#Returns the name of the socket the link is from
                    node.base_path=parentpath
                    node.label=socket_name
                    node.file_slots[0].path="\_"+"nom"+"_"+socket_name+"\_"+"nom"+"_"+socket_name+"_"
class FILE_OT_rename_file_outputs(bpy.types.Operator):
    """Renames file outputs"""
    bl_idname="render.rename_file_outputs"
    bl_label="Rename File Outputs"
    def execute(self,context):
        rename(context)
        return {'FINISHED'}
class FILE_PT_rename_file_outputs(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label="File Output Manager"
    bl_space_type='PROPERTIES'
    bl_region_type='WINDOW'
    bl_context="render"
    def draw(self,context):
        layout=self.layout
        row=layout.row()
        row.operator("render.rename_file_outputs",text="Rename")
classes=[FILE_OT_rename_file_outputs,FILE_PT_rename_file_outputs]
def register():
    for c in classes:bpy.utils.register_class(c)
def unregister():
    for c in classes:bpy.utils.unregister_class(c)
if __name__=="__main__":register()


The Principled Volume shader automatically picks up some details from attributes (eg, 'density' or 'temperature' and the Blackbody input can use this to generate the volume. This means it's not possible to change the Hue of the generated volume other than the Blackbody Tint - which effectively 'filters' the colours (multiply the RGB channels) - which loses some of the colour information.
The solution is to move the Blackbody colour generation outside of the shader and use the Emission sockets in place of Blackbody Intensity.
For a standard fire simulation this can be achieved with the following nodes :

Here the 'temperature' attribute node takes the place of the 'Temperature Attribute' in the Principled Volume node. The Multiply converts from the 0-1 range of the attribute into Kelvin (1.0 maps to 1000K) and the Blackbody generates the corresponding RGB values. The Hue Saturation node can be adjusted to change the hue without affecting the detail (change Hue from 0.5 to change the colour as desired).
Note that a maths node has been added to raise the 'flame' attribute to a power of 3. This seemed to be required to match the same intensity as that achieved when passing 'flame' directly into the Blackbody Intensity (presumably some conversion takes place within the Principled node itself).
You should be able to take this set up and replicate your results by using the 'density' in place of the 'flame' and/or 'temperature' attributes.
Here's an example of a standard Flame simulation with purple flame (Hue 0.2) to demonstrate the result :


Help with transitioning color with dynamic paint

First Suggestions.

Select for Brushes, for data value Paint Source

Mesh Volume + Proximity

as indicated by the Yellow Arrow. Image Above.

For the Canvas change Resolution to 128 for a higher resolution image and smoother transtions

See Yellow Arrow Image above.

I am not claiming this is the minimal set of changes.  You can test the two changes.

This is an improvement.  There may be other lesser problems.

OLDER

To have a circular or blob spread,  create a sphere or similar blob and use it as your paint brush. Your current box paintbrush is not going to fulfill your goals.  A sphere is a standard object and can be further shaped with proportional edit tool which can be searched here at BSE or the general internet.  This low cost improvement can be started by you immediately.
Experiment with the Dry and Dissolve features of Dynamic Paint.

Other suggestions may come later.  My time currently at BSE is expiring.


Your bones might be moved in the pose mode. To reset all the bones do the following.

Make sure you are in pose mode
Select all the bones
press Alt + G, Alt + R, Alt + S to reset position, rotation and scale respectively.

Without more information than you gave in those screenshots, I can't really help any more. There might be some issues if you used a mirror modifier. (because then you need to name your bones with .r (right) and .l (left) correctly.


In Blender there are 4 view modes, they are placed on the top right part of the viewport,  from left to right it's: wireframe, solid, material, and rendered view. I think the material view (the 3rd one from the left) is the one you're looking for.


How to Link/Append a data-block using the Python API?

Here's a solution. It appends an instance of the group (Blender 2.7x only):

import bpy

filepath = "/path/to/file.blend"
group_name = "CubeGroup"

# append, set to true to keep the link to the original file
link = False

# append all groups from the .blend file
with bpy.data.libraries.load(filepath, link=link) as (data_src, data_dst):
    ## all groups
    # data_to.groups = data_from.groups

    # only append a single group we already know the name of
    data_dst.groups = [group_name]

# add the group instance to the scene
for group in data_dst.groups:
    ob = bpy.data.objects.new(group.name, None)
    ob.dupli_group = group
    ob.dupli_type = 'GROUP'
    bpy.context.scene.objects.link(ob) # Blender 2.7x

Credit: solution is based on this answer: Import object without bpy.ops.wm.link_append

It's basically the same for objects:

import bpy

# path to the blend
filepath = "/path/to/file.blend"

# name of object(s) to append or link
obj_name = "Cube"

# append, set to true to keep the link to the original file
link = False

# link all objects starting with 'Cube'
with bpy.data.libraries.load(filepath, link=link) as (data_from, data_to):
    data_to.objects = [name for name in data_from.objects if name.startswith(obj_name)]

#link object to current scene
for obj in data_to.objects:
    if obj is not None:
       #bpy.context.scene.objects.link(obj) # Blender 2.7x
       bpy.context.collection.objects.link(obj) # Blender 2.8x

As of Blender 2.8 groups have been replaced by the new collection system:

import bpy

# path to the blend
filepath = "/path/to/file.blend"

# name of collection(s) to append or link
coll_name = "MyCollection"

# append, set to true to keep the link to the original file
link = False

# link all collections starting with 'MyCollection'
with bpy.data.libraries.load(filepath, link=link) as (data_from, data_to):
    data_to.collections = [c for c in data_from.collections if c.startswith(coll_name)]

# link collection to scene collection
for coll in data_to.collections:
    if coll is not None:
       bpy.context.scene.collection.children.link(coll)

Further information: https://www.blender.org/api/current/bpy.types.BlendDataLibraries.html


What could I improve on on my monkey model?

JUST SOME TIPS: The body part topology of your model is decent, though hands and legs' topology is too dense. Try to keep it as simple as it can be (start to model fingers using a circle with only 8 vertices).

Do the same for the toes (see my topology suggestion below).

Always start with a simpliest shapes and then slowly add more geometry.
Your question reminds me this one: How to retopologize my model? Wish I have more time right now to retopologize this model for you and show you some simple solutions, but I'm quite busy right now :(.

Remember, that simple and smart topology is a key to make the model bend well while animating (simple finger model topology bend example here: How do rigs relate to weights?)


The cycle toon render is not working properly

Set the angle to zero in the sun of light.
It also zeroes in the bounce of light.
Then you become a true toon shader.


UV Mapping identical meshes on top of each other

If the vertex orders aren't screwy, you can

In Edit Mode, P separate the identical components into their own objects
UV unwrap one of them
Back in Object Mode, with all component-objects selected and the unwrapped one active, CtrlL > 'Transfer UV Maps'
CtrlJ rejoin the components into one object.


How to make ik target overlap with its constrained bone's location

As far as I know, this is easiest to achieve, when the (first) constrained bone in the IK chain points to the target. I added a helper bone LowerLegHelper (which is the parent of Foot and Lower Leg) and added the IK constraint to it.

If you want Foot to be reoriented like IK_Target, simply add a Copy Rotation Constraint to it.


How to fix clipping when you have multiple clothing in 1 character

I have had this problem as well and I know that when you zoom in it usually goes away.

This problem is fixed when you render the image. When rendering, all the positions of the vertices are calculated correctly. In the viewport, positions of the vertices are estimated to save computing power. Therefore they might not look right.


Is their a way to queue or automate particle bakes?

The bad news is, no.
The good news is, yes!
From the Manual:

Bake All Dynamics
Bake all physics systems in the scene, even those of different types. Useful for baking complex setups involving interactions between different physics types.

So, you can't exactly queue, so if there's a specific order you want them to bake, I don't think that's possible without scripting your own solution.
But you CAN bake all the systems in the whole scene all at once by just clicking Bake All.


You need to either change the origin of the object, or use the 3D Cursor as a pivot point.

A quick way to change what is used as a pivot point, is to look at the bottom menu in the 3d view and select "Pivot center for rotation/scaling":

But to actually change the object's origin, you could first move the 3D Cursor to whereever you want the pivot point. To do this accurately, you can snap it to whatever you have selected (both in Object Mode and Edit Mode by pressing Shift-S and choosing "Cursor to selected".

Then, in Object Mode with you object selected, use the Object Tools menu on the left (T to make the menu appear if you don't see it), press Origin button, and choose "Origin to 3D Cursor".

-->

For Blender 2.8:

The 'Pivot Point' selector can be found at the top of your viewport in a drop-down with a double 'chain-link' icon on it


Can a Script node using OSL have a checkbox?

There is a thing called 'string widget' (metadata syntax), which may be of some interest. The OSL specs suggest it in page 18 chapter 4, but that syntax may not be implemented in cycles. I haven't seen any examples of its usage. (Except for vray - 3dsmax docs)

if Implemented from the specs, it would look something like this:

int clamp = 0
    [[ string widget = "checkBox"]],

The implementor, Dingto, confirmed on IRC that metadata is not supported - yet.


In the oultiner window the object has been disabled for rendering.

The Eye icon is to toggle object visibility on the 3D viewport.

The Arrow Icon toggles selectability.

The Camera Icon toggles rendering.
TO make the object renderable by enable the camera icon.


Black Spots and Corruption During Mesh Edit

All right I don't know. I guess the problem bred from the software I used to extract the model (Ninjaripper). It created a weird data layer of normals information (sharp-edge, smooth-face, etc) which doesn't show up in the viewport edit. It makes precious little sense to me, and the man-pages aren't very clear on the subject at all.

The fix as I mentioned above is to remove the data layer before editing, then replace it again afterwards.

Run it up the flagpole...


How to prevent my volumetric lighting cube to reduce my main light in the scene

If you are using volume scatter and/or volume absortion, some of the light intensity will be lost due to... scattering or absortion.

There is no need to change the materials for the other objects, just change the light intensity.

It is perfectly normal/valid to have high values as long as you get the results you want.

As a different note, the default values of 1 for volume absortion or volme scatter are usually way to high. Play with them and bring them down to get the effect you want.


According to what method is 3D cursor's location in 3D View determined when left clicking?

The 3D cursor moves in the plane facing the view you are in and intersecting its previous position.

Is you set up this configuration : a camera (bottom right), a plane (selected) 90° intersecting the camera view, you can notice this behaviour.
Go in the camera view using 0, click somewhere to move the 3D cursor, and come back to the top view. The cursor will stay on the plane.

The distance of the plane is defined by the normal vector N of the view (N normalized) dot the camera-"prev cursor position" vector. Or if C is the camera, P the previous position, the distance is ||N.CP||


How can i skin a model to a pose other than the Rest Pose?

I would suggest this: in the rig tab of your armature, create a pose library, and next a pose wich will hold the rest pose of your rig.

Next pose the rig as you like, make it the rest pose, work, and when you're done, restore the rest pose from the library.

BTW, maybe you can even make simpler: in the mesh object, modifiers tab, you can activate the 'Edit' button of the Armature modifier. Then you can pose your model and work on it, not only in 'Edit' mode, but 'Weight paint' too.

EDIT For instance, to rig a character already posed (i.e. being not standing straight), you can:

create a standard rig.
In pose mode, move the skeleton to fit the character body and limbs as accurately as you can.
Still in pose mode, parent mesh to armature with 'automatic weights'.
Then, if you return to rest pose, the mesh will follow.

Hope this helps


It is difficult to diagnose this without the Blender file. One issue could be that although the bones are parented to one another, they are not "connected". To correct this, go into edit mode, and make sure that "connected" is enabled for the bones:

Using L will select all bones that are connected though, which may include the entire rig, not just the hand, depending on your setup.

Alternatively, you should consider using Bone Groups for making such selections: https://docs.blender.org/manual/en/dev/rigging/armatures/properties/bone_groups.html


Micro displacement not rendering with motion blur. (Blender 2.79 )

As of 2.79, Cycles does not support adaptive (micro) subdivision and deformation blur on the same mesh. You should uncheck "adaptive" on the subdivision surface modifier if you need deformation blur.

See this documentation page from the main developer of this feature: https://wiki.blender.org/index.php/User:Maiself/Micropolygon_Displacement


How do I create a custom-keying set based on a built-in keying set?

Properties can't be added to a built-in keying-set, which isn't necessary. The keying-set Whole Character also includes ik/fk switch (among others).

Note that for walk cycles the keys for the root bone should be removed.

Related:

Coding your own "Builtin Keying Set"


How can I change the 3D View's background color to something different for each mode?

Set World Background on and run this script via Blender text editor.

import bpy

Modes = {'OBJECT':(1, 0, 0),
        'EDIT':(0, 1, 0),
        'SCULPT':(0, 0, 1),
        'VERTEX_PAINT':(1, 1, 0),
        'WEIGHT_PAINT':(1, 0, 1),
        'TEXTURE_PAINT':(0, 1, 1)}

def my_handler(scene):
    mode = bpy.context.object.mode
    scene.world.horizon_color = Modes[mode]

def register():
    bpy.app.handlers.scene_update_post.append(my_handler)

def unregister():
    bpy.app.handlers.scene_update_post.remove(my_handler)

if __name__ == "__main__":
    register()


How can I access bone's 'animation_data.action'?

Armatures store data differently than other objects, they contain a rest position for each bone that locates the bone within the armature structure as well as pose position used for animation. The data for an action is stored within a generic objects data, to get the armature animation data you want, you need to treat the armature as an object to get there. The path to the fcurves of the armatures action is

bpy.context.active_object.animation_data.action.fcurves

The list of fcurves in the armatures action will contain every curve for every channel of every bone in the armature that is keyframed, each curve has a data_path with a value like pose.bones["hips"].location, by extracting the name you can compare it to the selected bone names with something like -

bone_names = [b.name for b in bpy.context.selected_pose_bones]
...
for curve in fcurves:
    if curve.data_path.split('"')[1] in bone_names:
        # do stuff


Pressing Delete will delete the active ruler (whichever is selected or left-click to select a specific one) before having pressed enter (all the options in the help line are options for during the creation of the ruler).

If you have already pressed Enter you can re-click the grease pencil 'Ruler/Protractor' button to re-enable the rulers and go through the selection and delete process described above.

After pressing Enter the rulers are saved to a grease pencil layer, so you could delete all rulers at once via the grease pencil panel in the properties menu (N) in the 3D view by selecting the grease pencil layer in the list and then pressing the ' - ' (minus) button:


Importing C++ functions created with pybind11

So after some digging I found out, that this was caused by importlib.reload.
Blenders Reload Scripts-command only reloads the addon if the main file (in my case __init__.py) has been changed. (Also discussed here)
Since my addon consists out of several .py-files and I wanted everything to be reloaded if I hit the command, I used importlib.reload to manually force reloading.
I also used this technique on my C++-module, which you're not supposed to do!
Reloading C++-modules with importlib is not supported and may result in errors, just like in my case.
After removing this reloading instruction my C++-module works just fine in Blender. The only downside is, that I'll have to restart Blender, whenever I change my C++-module and want to see these changes in effect.


I cannot paint in the "Texture Paint" mode

Looks like inverted normals, try selecting that mesh and pressing CTRL+N or W>Flip Normals


Bone snapping to control bone while making an Inverse Kinematic Rig

Your problem has a very simple answer. When ever you add IK control to a rig, the  default chain length is usually $0$ and the bone tries to point at the rig's origin, thus creating some weird posture.
You can solve this by adjusting the chain length to the number of bone you would like to be influenced by the inverse kinematics(IK).
Try $1$ or $2$ and get a feel of what work best for the rig.


Anti-aliasing not working in Normal bake

TexTools for Blender was recently released (free) which adds an anti-aliasing option for baking.

Internally the add-on just renders at 2x or 4x the size and then down-scales the final bake to the target resolution resulting in anti aliasing. The good thing is that this anti-aliasing works with all bake modes in TexTools.

You can find more information and download links from my website.


bevel shader not appearing in 2.79 on Mac

Cycles Bevel Shader is an experimental feature introduced after the release of Blender 2.79.

It is available in experimental trunk builds post release but not in official ones.

It is to be introduced to general public as a new Blender 2.8 feature as stated in the release notes.

It should also be used sparingly since it is computationally heavy and resource hungry. In most cases it is preferable to use geometry based solutions since it is cheaper to render then the shader, unless you encounter issues or glitches with complex geometry.


How to make torch cutting logo out of a plane (steel) and falling pieces.?

Starting with a plane, you can use the knife tool K to cut a logo into it.

Then in face select mode select the faces you want to come out. Use P->Selection to break the selected faces into a new object that are located at the same position, so both objects will blend in as one. Note that a subsurf modifier will pull the edges apart and make the seam visible.

Now you animate the location of the piece you want to fall. Go to the frame you want it in place, say 20, and press I->LocRot to add a keyframe for the location and rotation. Move ahead a few frames and move the logo and add another keyframe. Repeat a few times to have it move and rotate as you want.

For the effects you can combine that animation with dynamic paint and particles.


If your question is: Is it possible?
Can't help you with the scripting but it's definitely possible to model the scenario.

You should easily be able to find out how to make a box and unwrap it. You may need to adjust the UV's to get the textures right. It may be easier to make a big texture of the 6 images.
Make sure you flip the normals to point inwards.


How do i animate a group rotating as one object?

When you rotate multiple selected objects and they all rotate about their own axis it is probable that your pivot point is set to 'Individual Origins'. This would mean exactly as you describe that each object selected will rotate about their own origin.

https://www.blender.org/manual/getting_started/basics/transformations/transform_control/pivot_point/index.html

If you don't really care about where they rotate about, you can just use the 'Median Point' as the pivot point, but if you want to make a precise rotation around a specific point, an easy way to do this would be creating an empty at the point of rotation and parenting all the objects you want to that empty. Then, you can simply rotate that empty and all of the parented objects will rotate around that empty. There are other ways to do this but from personal experience I think that if you are just doing a 2 key frame animation then using an empty as a center of rotation is one of easiest ways to rotate about a specific point.

Here is your .blend edited with the group parented to an empty cube and with the correct rotations.


Automate geometry creation to match texture UV mappings?

In short yes, but It could take forever to do so too. It could be much faster and easier to remove mesh faces at the eyes in the model and attach a modified sphere with UV Map/s (Duplicated) to display your details but ultimately depends on what your desired results are to be in the area.


Eevee. I'm getting this weird random light out of my model and also in the render

Turn on Screen space reflection , even I had problems and you don't have any solutions on the internet but this should solve you problems.


Object physics not working when moved with armature?

Using an armature to animate a (passive) rigid body using Armature Deform distorts the mesh, rather than actually moving the rigid body - this will affect the final visual state of the mesh but not its underlying location or rotation. The Armature Deform takes place after the simulation and so does not affect the simulation.

In your case you need to parent the 'container' to a specific bone - so that the bone is the Parent of the entire container (rather than using Armature Deform). The container should be a Passive rigid body since its location and rotation will be controlled by the bone, rather than simulated.

By default, the rigid body simulation does not take account of the animated locatation or rotation of the mesh - so the actual influence of the mesh is as if it is still in its original location - this is what you are seeing in your current simulation. However, if you enable the Animated property of the rigid body this tells the simulation engine to take account of any translation and rotation of the mesh before it is used to affect the simulation. This should now result in the contents being affected by the motion of the container, similar to the following :


Image Alpha Background Renders Black when using “Import Images as Planes” 2.0

In your particular case you did not enable

Use alpha:

In newer versions of blender that box might not be there but you can still select to have transparency as you import the image:

The trasnsparency will only show on Material or Render view, it will not be displayed in texture view.

For more details read the previous answer:
Image Alpha Background Renders Black when using "Import Images as Planes"


Vertex Group Weights disappear when I move the bone

Every modifier has three or four display options.

The first one shows the result of the modifier when rendering.

The second shows the result in the viewport.

The third shows the result while in edit mode

The fourth shows the result on the edit cage while in edit mode. Enabling this only works when the third is enabled.

By having the edit mesh options disabled, you will only see the undeformed mesh in edit mode. Enable both of these to have the edit mesh follow the armature.

While in edit mode, selecting bones has no effect on the display of vertex group weights. Select a vertex group in the mesh properties to change the weights displayed in the viewport.


How do I stretch a strip to work with the speed control effect without loosing footage?

Click and Drag on the End part of the clip with the minimal arrow to manually stretch it out and extend.  Make sure there is empty room to extend.  Use the correct side of mouse to click.  My mouse is differently set.

The panel also allows you to type in length. Press n to display panel.

Middle Click moves the entire strip. Do not click in the Middle for this task.


Is it possible to make a sequence of renders and give the user the option to cancel the process through the UI at any given time?

Yes! This is possible.

I finally managed to get it to work in a loop.
The current solution allows to cancel the operation with the X button in the Info Window and the ESC key. The images are rendered in sequence on the same frame without the need to create additional scenes or keyframes.
Render handlers are used to know the moment when a new render can be started. Then, a modal timer is used in a loop to start the render when it becomes available. I think this timer should be similar to the wait method of the threading.Event() object, but I failed making it to work with the render operator that way.

The problem with builtin modal operators like render.render is that these need to be wrapped and executed inside a modal loop to work correctly. If this is not the case, the older job locks, and prevents subsequent renders to spawn and start, making basic loops pretty useless. This is why additional scenes don't make a difference, because a render job can be executed once at a time in a blender instance.

So, to make it work, a new operator needs to be created. The actual render process stays inside the modal method, and handlers take care of signaling.

import bpy

class Multi_Render(bpy.types.Operator):
    """Docstring"""
    bl_idname = "render.multi"
    bl_label = "Render multiple times"

    # Define some variables to register
    _timer = None
    shots = None
    stop = None
    rendering = None
    path = "/tmp/"

    # Define the handler functions. I use pre and
    # post to know if Blender "is rendering"
    def pre(self, dummy):
        self.rendering = True

    def post(self, dummy):
        self.shots.pop(0) # This is just to render the next
                          # image in another path
        self.rendering = False

    def cancelled(self, dummy):
        self.stop = True

    def execute(self, context):
        # Define the variables during execution. This allows
        # to define when called from a button
        self.stop = False
        self.rendering = False
        self.shots = ["one.png",   # I'm just rendering 3 images but you
                      "two.png",   # can adapt to your needs
                      "three.png"]

        context.scene.render.filepath = self.path

        bpy.app.handlers.render_pre.append(self.pre)
        bpy.app.handlers.render_post.append(self.post)
        bpy.app.handlers.render_cancel.append(self.cancelled)

        # The timer gets created and the modal handler
        # is added to the window manager
        self._timer = context.window_manager.event_timer_add(0.5, window=context.window)
        context.window_manager.modal_handler_add(self)

        return {"RUNNING_MODAL"}

    def modal(self, context, event):
        if event.type == 'TIMER': # This event is signaled every half a second
                                  # and will start the render if available

            # If cancelled or no more shots to render, finish.
            if True in (not self.shots, self.stop is True):

                # We remove the handlers and the modal timer to clean everything
                bpy.app.handlers.render_pre.remove(self.pre)
                bpy.app.handlers.render_post.remove(self.post)
                bpy.app.handlers.render_cancel.remove(self.cancelled)
                context.window_manager.event_timer_remove(self._timer)

                return {"FINISHED"} # I didn't separate the cancel and finish
                                    # events, because in my case I don't need to,
                                    # but you can create them as you need

            elif self.rendering is False: # Nothing is currently rendering.
                                          # Proceed to render.
                sc = context.scene

                # I'm using cameras named just as the output files,
                # but adapt to your needs
                sc.camera = bpy.data.objects[self.shots[0]]

                sc.render.filepath = self.path + self.shots[0]
                bpy.ops.render.render("INVOKE_DEFAULT", write_still=True)

        return {"PASS_THROUGH"}
        # This is very important! If we used "RUNNING_MODAL", this new modal function
        # would prevent the use of the X button to cancel rendering, because this
        # button is managed by the modal function of the render operator,
        # not this new operator!

def register():
    bpy.utils.register_class(Multi_Render)

def unregister():
    bpy.utils.unregister_class(Multi_Render)

if __name__ == "__main__":
    register()

    bpy.ops.render.multi() # Test call

I hope this can help others if in the same situation.


Create a surface within bounding curves?

Add a Curve (Shift+A-->Curve-->Bezier) and model the first profile being in Edit Mode. When finished, select it (A), duplicate (Shift+D) and place as far from the first one as you want. Model the duplicated second profile as you like.

Go to Object Mode, change the curve's resolution (Preview U and Render U) to 3, then select it and press Alt+C-->Convert to Mesh.

Go to User Preferences (Ctrl+Alt+U) and enable the F2 add-on.

Select two vertices as pictured below and press F continuously to fill the gaps.

Add a Subsurf Modifier to the mesh to make it look smoother. Enable a Smooth Shading in the Edit panel of a Tool Shelf (T).


What is the number in corner of the 3D view?

It shows what frame on a timeline you already are. It is very useful if you e.g. maximized the window with View -> Toggle Maximize Area (Shift+Space) and don't see your time cursor (the green vertical line) on the Timeline. Please see how to navigate it btw (What are the hotkeys to navigate the timeline?).

It's also very helpful as it shows what frame on a timeline the animation keyframe is inserted (the number changes the color from white to orange then).


Align particle objects relative to parent mesh

Use "align rotation with the snapping target" in the footer of the 3Dview. You can choose dot or plane for snapping your cross.
See image joint: snap.png.


Issue with boolean modifier with self intersecting array

Check the "self" box in the boolean modifier. This solved it for me.


How do I keep the aspect ratio of an image imported to the 3d viewport as a plane?

Think of it this way:

A scene in blender is created in a virtual world.

The units for that world and all of the objects are blender units (that coincide with meters. one blender unit is one meter, the units can also be set to imperial measurements or KM or mm if you wish)

When you import an image as a plane, it will create a plane that is one blender unit tall (that can be changed in the options as you import the image), and that has the aspect ratio of the imported image.

The number of pixels in the image does not determine the size of the plane.

If you need to create planes that are different sizes and have their size relative to their dimensions in pixels, you could do that manually using the information on this link:

How to map an Image on a plane manually?

Do not touch the aspect ratio on the dimensions for the render unless you know what you are doing and need to export an image that is using anamporphic pixels. Read: Rendered aspect ratio different from the viewport's camera view


How do I make something like this in Blender?

Sort of. You can animate a mix mask with transparency for both models and keyframe the mix factor so they appear and disappear exactly when you want them to. Alternately, you can simply make two completely different scenes and composite them.


Applying materials on mesh models present in different blend files using python script

My first suggestion would be to avoid using bpy.ops and instead use code like http://web.purplefrog.com/~thoth/blender/python-cookbook/link-external-data-blocks.html which I have excerpted here:

import bpy

def library_get(name, data_blocks, libpath=None):
    """ Since it is possible for a .blend file to have several objects
with the same name linked from different files, this routine lets us
hunt down the right one. """
    for x in data_blocks:
        if x.name == name and x.library is not None:
            if libpath is None or libpath == x.library.filepath:
                return x
    return None

def addGroupToScene(grp, scn):
    for obj in grp.objects:
        scn.objects.link(obj)

#
#

fname = "//cube.blend"

print(fname)
with bpy.data.libraries.load(fname, link=True) as (src, dst):
    # src has many properties, each of which is a list of name strings.
    # dst is how we specify what we want to link from the library file.

    # let's link the "dazed" scene
    dst.scenes = ["dazed"]
    # and the "omnitile" object
    dst.objects = ["omnitile"]
    # and an object group
    dst.groups = ["frog"]

    # and just to be fancy, let's count up how many linkable things there are
    for dbt in dir(src):
        name_list = getattr(src, dbt)
        print("%s[%d]" % (dbt, len(name_list)))

# just because we linked an object doesn't mean that object is in any of our scenes.
omnitile = library_get("omnitile", bpy.data.objects)

scn = bpy.context.scene
try:
    scn.objects.link(omnitile)
    # now it is.
except:
    pass

# link all the objects from group "frogs" to the current scene
addGroupToScene(library_get("frogs", bpy.data.groups), scn)

Your version would probably have dst.materials = ["mainMaterial"]
and mat = library_get("mainMaterial", bpy.data.materials)


Your UV islands are too close together. Give each UV island enough space for the baking process to expand the colors beyond UV islands bounds.


Cycles Render reduces workspace by strange cube

It seems like there is some hidden object in your scene that is not visible in the viewport but still appears in your render.
With the mouse cursor over the 3D view, press Alt + H to unhide all objects in the current scene


As you can see, Loop viewer can display only one loop, not both. It clears every time, than loop 1 takes new value.

If you want to see result of Loop 1, pass value to output of loop 2.


The 'Linear' option is effectively the same as the non-color option elsewhere, since it doesn’t apply the sRGB conversions.


Controlling the direction of face selection?

It really depends on where you click with your ALTRMB.
If you click close to the vertical top or bottom of your face, it will select the vertical loop. If you click on the horizontal area, it will select the horizontal loop.


How do I use the compositor to render with different color management profiles?

I am reasonably sure this can't be done from within Blender. This is a design flaw in that baking colour transforms isn't dealt with in an optimal manner.

You could however save your images as scene linear and apply the transforms using other tools such as the command line tools from OCIO.


What are the appropirate axes for arm & hand rig with IK?

Your arm is twisting because, in edit mode, your Arm UpperL bone has a roll of negative 92 degrees, while the corrisponding FK and IK bones have positive 90, leading to a nearly 180 degrees twist when copy rotation is applied.

FK and IK chains bones should be created as duplicates (Shift D) of the deforming bones, so to retain exactly location and bone roll.

I fixed the problem adjusting the bone roll and manually trimming the pole angle of the IK constraints (negative 160), but the correct way should be to delete and reconstruct the IK and FK chains using duplicates of the deforming bones.

The initial angle is generally choosen having the X rotation aligned with the main rotation that will be used, which can help a little when editing animations in the graph editor, but is something like an habit, not a rule; the rule for avoiding twisting is to have the bones exactly duplicated.

Another IK trick is (expecially on legs) avoiding having the bones perfectly aligned, moving the knee joint a little forward, in this way Blender will automatically bend the leg in the right direction.

I suggest you also to set the subsurf modifier after the armture modifier (and set the shading to smooth).


Rotating each iteration of an Array Modifier

You can achieve that with the Array modifier alone.

Create an empty at the origin of your base pair and make sure it has the same xyz rotation.
Disable all offsets in the Array modifier.
Enable Object Offset and select the empty from the list.
Rotate the empty and move it up a little, so that it matches your helix.

The object offset uses the differences regarding location, rotation and scale to generate the array.

Another, older and in some aspects, more powerful way would be to animate the base pair rotating and moving up the helix and then turn on dupliframes in the Duplication panel of the object properties.

To get even spaces between the steps, you'd have to set the f-curve to linear interpolation.


Creating bottle using Blender Render for output to Blend4Web

Please see this model
https://www.blend4web.com/apps/webplayer/webplayer.html?load=../../assets/fridge/bottle/bottle.json
The source Blender file is only available in the Pro SDK though. Anyway, feel free to ask questions regarding this model on our forums.


Why we can't apply edge loop on mesh if we applied bevel first

If you bevel it can create ngons (faces with more than 4 vertices that are no longer quads), and you can't automatically create edge loops through ngons because it can't guess what opposite edge it is supposed to cut through. But you can cut with knife and recreate quads from your ngons.


The easiest way is to activate the selection of edges, select 2 or more edges where you want to fill with a face and press

CTRL + E
select bridge edge loop

You can also do this by selecting edges and filling by pressing F


Limit to number of parents an object can have?

A certain object can only have 1 parent in Blender. You don't need to worry about not being able to control the object the way you want to, because you can also control the parent objects, and so on and so forth. In my example I parented the hooks of the eyes, in which case if both are moved together at the same time will move the entire eye, to a single empty that will move the eye. I did this for both, and parented those empties to a third empty that rotated them around the sphere. Then I parented that empty to the sphere itself so that when I move the sphere, everything moves. I thus solved my own problem.


How to connect different bone structures from the same armature?

Sorry for asking, I eventually found it. It was actually a lot simpler than I thought! Pretty basic actually, I'm not sure how why it took me so long to notice.

Thanks anyway!


Wrong topology or just UV viewport's artefact?

Looks like some of your vertices are over-scaled on the Y (yellow).

It could also be from vertices that don't have an edge.

Try scaling down on the Y (yellow arrow below)


Exported .mtl does not specify the texture image

The textures color output should be attached to the color input of the shader (Diffuse BSDF in your example), for it to be exported into the mtl file.
Edit:
It seems the PrincipleBSDF shader node (instead of DiffuseBSDF) is needed for the .obj / .mtl export to function properly!


Why do faces appear transparent when exported to a game engine?

Did you try switching the normals?
If not, select the entire object whilst in Edit Mode. And press Crtl + N


It's in the (by default included but disabled) 3d print toolbox addon, but it changed the name, now is called "mesh analysis" in the 3d view properties panel (open with N)


How to export mesh with normal map applied as OBJ or STL for 3D printing?

Normal maps are an "effect" added on top of your model, visually changing the apparent normal (direction) of the surface at a certain point to simulate additional details.

This simulation affects shading only, like lighting, reflections effects and self shadowing (not projected shadows though). There really isn't any geometry or details there only distorted directions, so unlike displacement or bump these can't efficiently be added back as geometry.

Bump maps on the other hand store "height" values, in a black and white image. While these are also computed to affect normals only, they could optionally be used to move the mesh surface up and down according to black or white values and thus build crude geometry details, in a process often called displacement.

This process is also inefficient and a rough approximation of the original, it requires high amounts of geometry for a inferior quality result.

Bottom line is there isn't as far as I know an efficient way to add back details.

You could try and use the normal map in a displacement node, using the option RGB to XYZ and see if you get any decent results. It will require a subdivision modifier before it with a high count of subdivisions, but expect numerous artifacts and low fidelity.


Objects disappeared and only show up in final render

GUYS IT WAS LOCAL VIEW YOU CAN CHANGE IT TO GLOBAL VIEW ON THE "VIEW" OPTIONS OR TYPE "/" ON THE NUMPAD.

I was confused because i'm not a native speaker and people told me to type numpad/ which i  understood to be deactivate/activate the numpad.


The color of my object changes when I use Shadow Catcher

So, I figure the answer. It's because the first picture there is no plane under the head but the one with the shadow catcher has a plane which I guess reflects the light which brighten the head. My nodes setup is simple, it's principled shader to the material output.


How to enable animation for Eevee at this early stage on Mac

Ok figure it out myself, on the Terminal:

cd /Applications/Blender
./blender.app/Contents/MacOS/blender --enable-copy-on-write

cd /Users/username/Downloads/blender-2.80.0-git20180507.e3d30ffb920-x86_64
./blender.app/Contents/MacOS/blender --enable-copy-on-write


The gizmo category is not included in the keymap_hierarchy.py which can be found in release\scripts\modules\bl_keymap_utils. Therefore the category isn't displayed in the overview of the keymap. When you export the keymap you can view all shortcuts and it includes the ones for the gizmos.
It's not entirely clear to me why these entries are missing, hence I've created ticket T77799 on Blender's bug tracker. The reply by the UI team will be your definitive answer.


Is there way to move one vertex and make another move with it proportionally?

As pointed out by @MrZak you can use Shear (Ctrl+Alt+Shift+S)

Form the Blender Manual:

  Shearing is a form of movement where parallel surfaces move past one another. During this transform, movement of the selected elements will occur along the horizontal axis of the current view. The axis location will be defined by the Pivot Point. Everything that is “above” this axis will move (Shear) in the same direction as your mouse pointer (but always parallel to the horizontal axis). Everything that is “below” the horizontal axis will move in the opposite direction.


Blender 2.8: How to select edges behind other edges when in numpad 1 mode

To be able to select occluded geometry you must enable the viewport option X-Ray.

Either use the button on the 3D View Header or press access the with Z key Shading Pie Menu > Toggle X-Ray.


How can I achieve an "blinded by light" effect?

This will most likely be hard to achieve through the 3D scene alone, and will probably require some post processing and compositing work.

It could probably be achieved with a mix of lens flares and god rays and volumetric lighting.

Volumetric lighting can be made with a volume material in cycles, see this: Project light through shape, text or symbol to appear in cloud or mist

It can also be faked or enhanced in the compositor with the Filter > Sun Beams node.

In compositing you can also add a lens flare effect with Filter > Sun Beams or Filter > Glare

Blender God Rays Tutorials
Blender Lens Flare Tutorials


Currently to_mesh is the only way of getting evaluated mesh from within edit mode.


Converting Quaternions to Euler in the Graph Editor

Select the camera object, (still in quaternion rotation mode) copy script, paste into text editor, run script.  It will create a set of rotation_euler fcurves matching the quaternion rotation.  If all goes well manually change the rotation mode and clear the quaternion keyframes.

import bpy
from math import tan, atan
context = bpy.context
scene = context.scene
order = 'XYZ' # euler rotation order desired
cam_obj = context.active_object
action = cam_obj.animation_data.action

frames = []
fcurves = []

for index in [0, 1, 2, 4]:
    # search for rotation euler kfps
    fc = action.fcurves.find("rotation_quaternion", index=index)
    # make a list of frames that have quaternion rot keyframes
    if fc:
        frames.extend([kfp.co[0] for kfp in fc.keyframe_points])
        fcurves.append(fc)
# run thru and keyframe in

for f in set(frames):
    scene.frame_set(f)
    cam_obj.rotation_euler = cam_obj.matrix_world.to_euler(order)
    #cam_obj.rotation_euler = [atan(tan(d)) for d in cam_obj.rotation_euler]
    cam_obj.keyframe_insert("rotation_euler", frame=f)


Blender character to unity scale problem

I solved it. Scene -> Units -> Set it to centimeters.


My object is keeping its original shape aswell as adding the additional movement

Caught green handed. Your subdivision surface modifier is set to 0 subdivisions in the viewport (though the render levels are at 2). Also, it is animated. Right click -> clear keyframes, or any manual change will be cleared if you accidentally switch frames.


How do I optimize my large grass system to render quicker?

I think the best way would be to have very low poly grasses with very low Res textures. But it's not very evident. In my knowledge, at the moment, there is not the equivalent of adaptive subdivision for the hair particle.
On the other hand, I noticed that former versions of Grasswald used less graphic-card memory, than newer, in rendering but it uses still more memory than low poly particles you can model yourself. To go further, the last Grasswald version has an adaptive weight painting depending on the camera's fieldview. But it doesn't works with videos because, when you change the weight painting, the particle system will randomly change each time you change this weight-painting. That's to say if your camera make a travelling, the particle system would randomly change on each frame.
I will make my video but only with grass micro-displacement texture (with adaptive subdivision) instead of any particle system.


Check this out:

I will circle back around to polish the build instructions, but the things that make this work is adding a shrinkwrap constraint to the location of the empty (that is being rotated in the following animation), parenting the Iris/Pupil mesh to that Empty, and adding a shrinkwrap modifier to bend to the shape of the eyeball (the trick on this one is to set a small offset, and check keep above surface).

For an extra, I added a shapekey for the pupil dialation.


I get border artifacts when using Cryptomatte or ID Mask

Good news! This has been solved. Our friends at CG Cookie actually made a video in 2013 (before Cryptomatte) that explains the problem and a solution we have when working with a flattened scene: Working with Alpha Edges for Compositing in Blender.  No matter how perfect the matte is, even Cryptomatte cannot solve the subject / background color mixing on the edges. However, the video shows how to use nodes in Blender to get around this! Essentially, you duplicate and invert the matte and apply it to the background, and use Inpaint node on both the foreground and the background to simulate and extend edges of unmixed color. Here is a basic node setup. Note that the ColorRamp nodes each have a black stop and a white stop, they're just VERY close together but they don’t necessarily have to be if your edges look clean:

The techniques work great with Cryptomatte, and solved my edge issues very well. In fact, I believe their Blender compositor approach is the same basic principle used in the Fusion solution linked in comments above. Knowing this approach, it's also useful for working with other types of flat footage that requires mattes and decontaminating the edges of color blend from subject to background.

Another solution would be to use separate render layers via linked scenes and collections, then composite those, but that is not always practical or possible. It would be amazing to have an automated way to render separate layers based upon the Cryptomatte (would probably only work at object level, not material level), or maybe get some kind of deep compositing method like this video shows: Skill Up With Nuke | An Introduction To Deep Compositing In 11.2. Eevee and Cycles do not have deep compositing at the moment, but perhaps another render engine compatible with Blender does have it.


How Do I Make an Object Look Two-Dimensional, But Have The Rest of My Project 3D?

I would suggest looking into using render layers and combine with Z depth, and that way you can set up freestyle ONLY on the layers that have the characters then.


other objects push on bone controlled surface?

Here, I've set up a simple box that is weight painted so the main bone only influences the flap.  The tip bone is there for the IK setup.(not sure I did this entirely right since I'm still just learning this as well)

Anyways, here are a few pics.  First you can add a loopcut to the edge of the flap to limit the weight paint so the bone does not affect the rest of the box.

Now the weight paint setup.

There is an Empty added near the tip of the IK controller bone which is referenced in the IK constriant which I added to that bone as shown next.

I also added rotation locks to both bones so they can only move in one axis.  The image shows 2 places where this can be done.

Next is an animation showing the result of moving the Empty.


Compositor and rendered image not the same

This is because in your file, the image viewer is set to display the "Bangle" renderlayer:

Select "Composite" instead to view the output of the compositor.


How to use global XYZ coordinates for displacement?

The vector displacement space for RGBtoXYZ mode is always local, unfortunately. (tangent would be useful in a lot of cases too). The good news if you need global space though, is you can apply your rotation (object > apply > rotation from the 3d view header) and bake your rotation into the mesh. This gets rid of the object level rotation meaning local space = global space once again.


So here's the plan:

to import all the armatures into 1 file
to run a script to compare them between each other and export the names of bones they have in common.

Importing (several options):

Just CtrlC, CtrlV from a file to another.
Or ShiftF1 to append an object. Navigate to a .blend file, select Object, and pick the armature object.

After all the armatures are in the same scene, switch to Scripting screen layout.

you can select it from the top menu bar (you should be in the Default screen now)
or you can use  CtrlLeft Arrow and CtrlRight Arrow to switch between the screens.

In the Text editor, make a new text file and paste the code in:

import bpy

bone_names = []
for armature in [ob for ob in bpy.data.objects if ob.type == 'ARMATURE']:
    for bone in armature.data.bones:
        bone_names.append(bone.name)

common_names = set([name for name in bone_names if bone_names.count(name) > 1])

print(common_names)

Run the script, it will print the output into the Console window (Window > Toggle System Console).

If you want to print it into a text-file or json-file that's easy too just give me a file-path and I'll edit the script.


Python - Trouble when changing context (the first time)

To delete the nodes you should override the context of operator bpy.ops.node.select_all.
And the reason of error you see is mentioned here.

Actually to delete the nodes, instead of using operator I would use next piece of code:

for node in mat.node_tree.nodes:
    mat.node_tree.nodes.remove(node)

updated with your part:

import bpy

mat = bpy.data.materials.get("Material")
geom = bpy.context.active_object

if mat is None:
    # create material
    mat = bpy.data.materials.new(name="Material")
# Assign it to object
if geom.data.materials:
    # assign to 1st material slot
    geom.data.materials[0] = mat
else:
    # no slots
    geom.data.materials.append(mat)

# delete nodes
for node in mat.node_tree.nodes:
    mat.node_tree.nodes.remove(node)


How to make my hillshade bright as given in the link?

This is matter of lights in your settings as also said susu in the comments.
Just an example from your file (but with another texture because you did not pack your texture in the file).

Only things changed are the lights.
I've changed the point light by a sun light and gave it an orientation and a strength of one (= one solar unit, our sun).

And added an environment texture (you can take hdri textures from Blender's install directory, in the data part):

From that, up to you changing color, texture, light intensity, etc.


Using a screw modifier and knife boolean

Start off with a cylinder. Duplicate one polygon and separate it off into its own object.
Extrude the face out into a box.  Make loop cuts in the box.  Select one face at a normal to the cylinder then invert the selection and delete all the other faces.  You should have a face that's aligned with the cylinder edge and at a normal to it.

Add a Screw modifier.  Ensure the number of steps agrees with the number of sides on the cylinder.  Adjust the settings until you have the desired spiral for your thread.  Apply the modifier.

Join the screw and cylinder objects into one mesh.  In edit mode, select the cylinder polygons and click Intersect (Knife) on the Face specials menu.  The screw polygons are no longer required so can be deleted.

Add a couple of edge loops to the main thread spiral.  Then use the inset polygon tool to bevel out the thread itself.  Adjust the start and end of the thread so there is a smooth transition.

The resulting topology leaves 4 ngons, but I like how they subdivide so I leave them in. Converting to all quads is possible with some thought.

The final render


Your object that you want to explode is one solid object. In order for it to explode you must first break it up into pieces.

I took the following steps:

Edit mode >Remove doubles
Object mode run cell fracture
Move object on layer one to a secondary/ unused layer and
move fractures to layer one
Add active rigid body physics to all fractures with collision margin
enabled at 1

Bake simulation then play the animation


This can be done with one driver and one look-at constraint.
The height of the piston-pin above the center of the crank is given by the following expression:
h = r * cos(A)+sqrt( (l**2)-( (r**2)*(sin(A)**2) )  )
where r is the radius of the crank, l is the length of the rod, and A is the rotation of the crank, as explained here.
With a crank of radius 1, and a rod of length 4, as illustrated, this reduces to:
sqrt(16-(sin(A)**2))+cos(A)
so this is the sort of expression you can put into a driver for the height of the piston(-pin), where A is the angle through which the crank is rotated.
The rod simply has to be parented to the crank, with its origin on the crank's circumference, and given a Locked Track constraint, making it look at the piston-pin.

If you parent both the piston-pin and the crank to another object, their transforms are evaluated in that object's space, and so the rig can be freely moved around, using their parent. In the example blendfile, it's the Empty called 'Basis'.


Can a surface reflect in black and white?

You can use the light path node. This node allows you to use different materials for each incoming ray type.

However, this approach is not ideal, since you have to modify the object's material and not the glossy material itself, which becomes almost unmanageable quickly.


Partially high noise using glass material

Your lighting is using very bright mesh lamps and this isn't helping. You can get much better results by using Area lamps instead. Also, Branched Path Tracing can produce much better results with significantly less samples.

Here are the result I got with just a little tweaking :

This is simply using two Area lamps replacing the mesh lamps (scaled to the same size), each with Emission of 15 and with my own HDR image for environment (yours was missin). I swapped to using Branched Path Tracing, removed Clamping and Light Sampling limits and adjusted the Samples to favour Diffuse and Glossy. I also set the Render AA Samples to 10.


Error while exporting a mesh from Blender Spark AR Toolkit V1.1.0

I also encountered this bug using the Blender 2.91. After some spelunking the the Toolkit's code and the Blender Python API I found a solution. Apparently something changed in the Blender export scene glTF API. When the Toolkit tries to export to glTF it passes the boolean value TRUE to the export_materials argument of the export function. However, it seems the export_materials argument no longer accepts a boolean value, but instead requires an enum value type. I tested it with the EXPORT enum value and that seemed to work fine.
I've already reported this to the Facebook Spark AR team and I expect an updated version of the Toolkit to be released in the near future. But if you really want to fix this now, you can do so by editing a Toolkit source file.
First close all running instances of Blender. Then locate the file spark_operators_export.py. It's location is mentioned in the error message that Blender displays. In your case it's /Users/kaiyawilson-smith/Library/Application Support/Blender/2.91/scripts/addons/Spark AR Toolkit/spark_operators_export.py. Edit that file using a plain text editor like Notepad.
Change line 66 from
export_materials=True,
to
export_materials='EXPORT',
Restart Blender and exporting your mesh should work again.


Add a Circle with 6 vertices and extrude it (E). Subdivide it adding edge loops (Ctrl+E). Snap the cursor to the top edge loop (Shift+S-->Cursor to Selected). Enable the proportional editing, increase the editing ring with Mouse Scroll and rotate (R) the top edge loop as pictured below.

Add the Solidify Modifier and play with its Thickness value.


Apply scale/rotation - shrinks mesh/rotates mesh 2.8

Reset Delta transforms to default values before other operations. Then you can move, rotate scale the model in object mode as you want; then press Ctrl A and choose Apply All Transform.


Where to set 'use_blender_profile' option?

You find the setting in the exporter's option pannel:

Note that this is a new option (added in june 2016). This option will become available in Blender 2.7.8. Of course you can download the most recent nightly build. There you should find this option as well.


Removing internal surfaces from overlapping spheres

In the end, I didn't end up going with a blender solution at all. I tried to implement the solution @batFINGER suggested, but my model wasn't properly formatted; the spheres in my model were not separate objects. When I tried to separate all the spheres into separate shells, blender crashed on me.

What did work for me was to load my object into Meshmixer and using Edit > Make Solid. Doing this created a solid object, filling in the entire shape. Using 'Preserve sharp edges' mode and maximizing 'Solid Accuracy' and 'Mesh Density' prevented too much detail from being lost. After this, I used Edit > Hollow. The final result was a shell containing only the visible surfaces of the overlapping spheres.


How can i export my models without any offset

Try centering the object in the center of the world before export using ⎇ Alt G and if your model moves into a weird position, move the model to the center manually and use ⎈ Ctrl A to apply the location and export afterwards.


change and update Spot Size when camera lens change?

Note : This answer relates to the interpretation of changing camera angle as being to change the actual camera, rather than the properties of the camera - which was not the actual intention of the question. I have left this answer in place since it may be of use to someone searching for related issues and it does describe an apparent issue in the OpenGL render.

After running some tests, it seems that there is a problem in the behaviour but I don't quite get the same results. Most notably, my render preview mode does correctly update and the actual render also appears to work correctly - the only issue I did find is in using OpenGL render where the light cone was not updated.

Here's my setup :

I've created two cameras and added markers to the timeline - one at frame 1 and another at frame 20. These markers are bound to the relevant camera so that the view starts at the first camera and changes to the other on frame 20.

I've set the Pass Index on Camera #1 to 1 and Camera #2 to 2 and the driver on the spot lamp size is set to 'bpy.context.scene.camera.pass_index /2' - since it's in radians this will be 0.5 radians (28.6 degrees) for the first camera and 1.0 radians (57.3 degrees) for the second camera.

If I render the animation I get this up to and including frame 19 :

And this on frame 20 and beyond :

Manually skipping through frames produces similar results in the 3d Editor window, whether in Render Preview mode, Solid or Wireframe :

Where I do get strange results is if I do an OpenGL Render - in which case the lamp size wasn't being updated (note the lamp cone lines not changing their spread) :

However, if I moved the timeline frame to be after frame 19 then the OpenGL animation did work correctly! (note the change in spread of the light cone - only change is the 'current' frame in the timeline at the time the render is triggered) :

So, in summary, there does appear to be a problem - and a problem that is dependent on the start frame in the timeline at the point the OpenGL render is actioned. I don't know if the same issue could potentially occur in 'full render' - perhaps I just didn't hit the same situation. More extensive testing required.

Note that my tests were all performed on Linux using Blender 2.76b.

EDIT I repeated the test using 'full' render and the lamp size in the final render did correctly change - so this looks like the issue is restricted to OpenGL render (at least, in my case). It would be interesting if you could repeat the tests. I'll upload my Blend file so you can test with that if desired.


You would just need to add another keyframe for the second object that should stay on its current position until the first moving object has finished its movement. Otherwise the position of your second object would also be interpolated between the keyframes.

In this example the location of both objects is keyframed at frame 1 the sphere reaches its final location at frame 20. The cube stops at frame 42. To have the cube stand still another keyframe for the cubes starting position is added at frame 20.


Looking at the chain link icon beside the object name, you didn't Append the object but Linked it.

You can't move linked objects directly, you have to use a proxy (old way) or a library override (new way).
If you want to retain the link to the original file, right click on the object in the outliner, then go to ID Data > Add Library Override.
The outliner should look like this :

If you want to have the object act independently of the original file, like it would if it had been appended, you need to right click on the object in the outliner, then go to ID Data > Make Local.
The outliner should look like this :


This can be done with insetting the faces. First select the faces you want to extrude. Then hit I button to bring Inset operator. In the operator panel, thickness value changes the scale and depth value you changes the extrusion depth.


Quite nice result with Cloth Sim + Empty

Under Physics Properties Enable Cloth Simulation, Preset > Rubber > Vertex Mass decrease to 0.3 kg
Create two Vertex Groups, one for Pinning second to Hook Empty

Pinning - select left two line of vertices + right-down vertex, add a new group and assign. Select second line of vertices and lower weight to 0.5

Hook - for this vertex group select only right-down vertex, add a new vertex group and assign

Snap cursor to Selected (Shift+S), go to object mode and add Empty.
Select page and add Hook modifier above Cloth with Object > Empty, Vertex Group > Hook. As a last moodier add Subdivision (with border vertices selected press Shift+E+1 (Crease) to keep sharp edge shapes of page.

Tip: to affect curvature at book binding slide second edge more left or right or add one more edge loop ...


How can I make a tower of stacked boxes stable in the game engine?

Put collision shape to box and increase  linear and angular damping up to your needs. Remember higher the damping, higher the viscous effect will be (honey like). I suggest to start with 0.3 for both and then try to tune them up until they are stable.


@Monster comment made me remember that I used to use shape keys in eyelid movement. Now, I'm using bone deformation (because of someone suggest). To make any eyelid-system, I need to drive the influence of "something".

Using Bone Deformation: I have to drive some constraint influence.
Using Shape Keys: I have to drive shape keys value.

In BGE we can't drive constraint influence, but we can do it with Shape Keys values. So, the second method is the suitable one for me (at this moment).

I make a new file, with a Shape Keys based Eyelid-Movement here: http://pasteall.org/blend/41589

It respects the eye (bone) rotation (to raise and lower the eyelid.2 automatically).
When I close the eyelid (with eyelid.1 bone), eyelid.2 stands still.

How the system works:

eyelid.1 is the bone to animate.
eyelid.2 copies eyelid.1 location (using Offset) and it has an Action constraint, to move itself when the eye is moving.
The mesh has a shape key eyelid.down that is driven with Minimum Value by two variables using eyelid.1 and eyelid.2, both with Transform Channel in Y Location at Local with its respective bones.
The shape key eyelid.up is driven by the same variables, but with Maximum Value and with the inverted curve.

... it's better to see the blend file.