Procedural materials applied with Planar UVW mapping seams to render like simple Planar UV in Raytraced display mode. This worked well in the past and according this post procedurals should be natively supported by Nvida GPUs (as I have). Anything broken?
In Rendered display mode and in Rhinos Legacy Renderer materials still look like they should.
They’re indeed mostly supported, but there is an issue with a couple of the procedural noise and the UVW mapping that I cannot solve properly at the moment without huge rewrite of a part. Proper fix for this will happen in Rhino 9.
RH-81821 Multiple mappings and primitive mappings need improvements
Since this inability will remain a permanent part of Rhino 8 I ask (not being at my Rhino computer to check myself): Is this limitation documented in the help? If not it probably should be.
You and some users would call it a bug, but at this point in time in V8 it’s just a limitation or unimplemented feature. The fact that trying to do it produces junk instead of of some kind of “can’t do this” message is the bug.
…and if you care about Planar UVW mapping, please also take a look at what happened to the bump channel. As far as I can see, this is completely ignored in Cycles:
Bump strength issues are known, too. In Tools > Options > Advanced search for two RhinoCycles settings that have the word Bump in them. For this scene set BumpDistance and BumpStrengthFactor both to 100.