In future use cases, a volume can contain many grids that represent the density information. In this case, it's better if the volume to mesh node creates a mesh based on all of the grids in the volume. This is also a benefit to share-ability, since one doesn't have to specify the grid name in the node. Instead, in the future we can have a way to split particular grids into separate volumes, if only one grid should be considered. The code changes are relatively simple: - Move the old volume to mesh node to the legacy folder. - Run the volume to mesh node on all instance geometry, like elsewhere. - Make the blenkernel's volume to mesh API a bit more specific. Differential Revision: https://developer.blender.org/D12997