Function meshopt::shadow::generate_shadow_indices

pub fn generate_shadow_indices(
    indices: &[u32], 
    vertices: &VertexDataAdapter<'_>
) -> Vec<u32>

Generate index buffer that can be used for more efficient rendering when only a subset of the vertex attributes is necessary. All vertices that are binary equivalent (wrt first vertex_size bytes) map to the first vertex in the original vertex buffer.

This makes it possible to use the index buffer for Z pre-pass or shadowmap rendering, while using the original index buffer for regular rendering.