I guess the addition OSL slips under the radar for most (it's slightly under-presented in the announcements) but it's actually a super powerful thing:
- code your own texture maps
- code your own things that do things with maps - blends, scatterers, coordinate transforms, color transforms
- all compiled with a click of a button and instant update in IR
- easy to keep track of - install by putting .osl files in the OSL plugin folder, create your own subfolders in there and Max automatically adds these as subcategories in the OSL map category
- OSL shaders can either load from disk or be stored within the OSL map in the scene, total user control here
- works with any renderer that supports Max shading context (Vray/Corona work fine)
Actually, most of the maps that don't lookup geometry or scene nodes can be rewritten to be purely OSL. Some things like node lookup are working with certain limitations, that way you can build interesting things like a A-B gradient that will read positions of scene objects for A and B and lets you move the gradient by moving these nodes, without touching UVs or having to update the shader.
There are plenty of use cases for OSL and the possibilities are crazy good. It's NOT meant to cast rays so certain things are not possible, but anything that creates and maps a pixel can be done. It's safe to expect a LOT of user generated OSL content once it's out there. The implementation is really good, convenient and well thought out, let's see what else they'll add to it.
