Well it is pretty obvious that you should use it when you have shaders that have high roughness to avoid the dark areas. notice that the amount of darknening is directly proportional to the roughness of the shader, so if you have a semi low roughness you don't have to use multiscatter.
To understand it, try a simple glossy shader in a white furnace test - no lights, just a fully white background and fully white shader color. At low roughnesses there is hardly any difference between GGX and GGX Multiscatter. At high roughness, GGX looses energy - it becomes darker at glancing edges where it should still remain fully white. GGX multiscatter behaves much better and remains nearly perfect white.
It would be great if anyone could manage a scrip to transform multyscatter into instanced objects. I cant use my old max 2014 scenes with multyscatter because i dont have multiscatter for max 2015, and its just to much geometry to collapse to mesh.
I have a multiscatter object, in this case a strip of grass, using a texture in the object colour slot. Looks great rendered on my machine. When trying to render with Distributed Bucket Rendering the buckets rendered on the other machine (set up identically) come out without that texture.
I have tried all sorts, from setting it to UNC paths, reinstalling multiscatter, replacing user paths on second machine. I'm starting to think this might be a bug as other multiscatter objects that don't use the object colour slot render just fine.
Sadly that didn't do it. Imported the grass object and made sure all the textures were within my scene file, as well as any xref'd files. I've included an image of the problem. Dark area rendered by other machine, vegetation in back is also multiscatter, but not using object colour.
Object color is applied to multiscatter instance, and not to underlying geometry. The problem lies within how Multiscatter exports its information of nested map inside it's instance. Try putting the material into material editor, and instance it from there into multiscatter but leave the material in editor for 3dsMax to correctly export the texture.
Are you using bitmaps or just the multiscatter texture? It seems to me that your render nodes can't access the bitmaps and xrefs so you need to make sure all your paths for bitmaps and xrefs are UNC and not on mapped drives.
This is the preset of vegetation for using in 3Ds Max with multiscatter plugin. Also used megascan models.
- Scene has 8 named multiscatter layers
- Scatter surface has mapping and 2 noise modifyers, whitch you should paste to scatter surface in your scene