I would like to create an atmospheric effect, and looking for a way to make a volume with a gradient density.

The scale is huge, and I am having problems with spheres mesh -> vdb, even if I make them small and transform/scale after VDB is created, I have problems with sampling it right to the renderer.

Karma Fog seems to work, but when I edit its contents to try to make a ramp, it crashes. Also, there is a Karma Render Settings node set for Uniform Volume... I am not sure at this moment how to make it work.

Temporary solution was to create few karma fogs with different radius (spheres) and change some parameters to make it look like a gradient.