LaurieA: I've just done another few tests using control loops (with and without bevels) as per EldritchCellar/primorge's other thread. Control loops alone (4) don't seem to work if I render with displacement and smoothing, but control loops plus bevel (5) do (slash-separated numbers are vertices/edges/faces). Meshes (3) and (5), both with control loops plus bevels, seem to work best here - but both have meshline/shadow artefacts, which is the second part of what I'm looking at...

EldritchCellar: I still haven't fully formulated my questions regarding the black shadow/meshline artefacts, but I think you've answered them already! :D (However, I'm still going to attempt to formulate my questions just in case there's something you haven't answered yet)

I often forget to convert the 0.0 to 1.0 range value of a displacement map to -0.5 to +0.5, but I remembered to do that here. That will obviously help any displacement related artefacts by halving the maximum displacement produced by the shader while keeping the range of displacement (although I think I've seen problems peculiar to negative displacement,although that may just be be befuddled memory confusing things - which is another reason that I wanted to get this big batch of test renders uploaded)

I'm fairly sure that using depth-mapped shadows without AO or IDL avoids just about all these light/shadow/meshline artefacts even with my large displacements.

As you said ray-traced shadows seem to be the major cause - I sometimes think it looks as if the ray-traced shadows are cast by the undisplaced mesh (which could be why I think negative displacements may cause additional problems?), but other times I think that can't be right...

I've also found that AO is also a big cause of meshline artefacts for the materials I like playing with (e.g. the "Sand Test" picture in my gallery here picture

I know I've seen artefacts with IDL but they're not showing on the renders I've uploaded so far on this thread.More test renders required.

_P.S. I've also found that combining noise, cloud, etc nodes with whatever I have plugged into bump and/or displacement can go some way towards making the artefacts less obvious... _

---

The 3Dcheapskate* occasionally posts sensible stuff. Usually by accident.
And it usually uses Poser 11, with units set to inches. Except when it's using Poser 6 or PP2014, or when its units are set to PNU.

*also available in ShareCG, DAZ, and HiveWire3D flavours (the DeviantArt and CGBytes flavour have been discontinued).