[Available from version 2025.1 Beta1 - 16.01]
Rest attributes remove texture shifting/distortion when using a texture projection that is not UV mapped (no UVs on the mesh) on a mesh with animated vertices.
When enabled, the projections will use rest vertex positions and normals to calculate the UVW coordinates.
Rest attributes don’t change during the animation so the texture mapping remains consistent.
Ref: viewtopic.php?f=33&t=84310
Here is a sample:
There are 2 objects with animated meshes.
The Rest attributes are enabled with the Octane Geometry properties modifier.
Rollout 'Misc' :
Use Rest Position
Use Rest Normals
Rest Pos frame
Note that the Rest Pos frame is set to frame 20.
Settings for the textures applied to object:
Box and Cylindrical projection are used, and the Use rest attributes is enabled.
Note that those projections discard the existing UVs set in those particular meshes.
The Rest attributes will work with meshes that have no UVs.
Move the timeline, and observe that the textures are 'un-deformed' at frame 20, and for other frames, the vertices will keep the same UVs as in frame 20, deforming the texture accordingly.