Multi Channel Texturing
It appears as though VTK might support multi channel texturing, given some googling history. Especially given this commented out line of code in our code: https://gitlab.kitware.com/iMSTK/iMSTK/-/blob/master/Source/RenderingVTK/RenderDelegate/imstkVTKSurfaceMeshRenderDelegate.cpp#L571
Multi channel texturing is useful as it allows multiple sets of texture coordinates on an object with different textures that are then blended together. This is particular useful for cutting where cut faces almost always have another texture. But also other effects & general texture changes.