GraphicsBuffer The skinned mesh vertex buffer as a GraphicsBuffer.
Retrieves a GraphicsBuffer that provides direct access to the GPU vertex buffer for this skinned mesh, for the previous frame.
During motion vector rendering (used for motion blur, temporal anti-aliasing, or other effects), skinned meshes that have skinnedMotionVectors on alternate between two GPU vertex buffers. You can access the GPU vertex buffer for the current frame using GetVertexBuffer, and for the previous frame using GetPreviousVertexBuffer.
You can use this method to access the skinned mesh vertex buffer for the previous frame in a ComputeShader. To do that, first request an appropriate buffer binding target via vertexBufferTarget, then get the graphics buffer using GetPreviousVertexBuffer, and then set it up as a parameter for your shaders using ComputeBuffer.SetBuffer, Material.SetBuffer and similar methods.
Additional resources: vertexBufferTarget, GetVertexBuffer.