The Volumes tab lets you specify Additional.x/Additional.y/Additional.z grids to be assigned as Absorption/Scattering/Emission. Does anyone know how these are intended to be used and how they are different from specifying the grid names directly? I don't see these options in the docs (for any plugin) or in the Standalone app, and it's confusing that they let you specify a vector input for Absorption/Scattering/Emission considering that the Volume Medium only works with float values for these quantities.
It would be great if Volume Medium supported vector Absorption/Scattering grids for rendering colored smoke, but as far as I can tell, this doesn't work even when using the Additional.xyz grids.