Hello everyone. I am using Karma and MaterialX for the first time, and am having difficulty setting up displacement maps from various packages, ie. ZBrush, Substance Painter, Mari, etc. I am encountering severe inflation or loss of details from my displacement maps.

Typically, when authoring materials in Mari, my maps start out with a mid grey value of 0.5 and then procedurals or any XYZ maps will be projected on. ZBrush displacement is always exported as 32bit exr with the mid value set to 0.5 as well. When rendering in Maya with Arnold, all I would need to do is set the offset of 0.5 and away we go. However, attempts to do the same with Karma have not been successful, aside from Mari.

Working in the Solaris desktop, I've imported my models and created a Karma Material. My maps are imported with the MaterialX Image node, set to float, raw and UDIM. If I plug directly into the default displacement node, it is exploded. I have added a remap node and have tried various values. It appears that a remap of -1 and +1 yield the best results while setting the displacement scale to 0.01 for my Mari textures.

ZBrush is another story though. Using the same settings but changing the displacement scale to 0.05 still has inflation on the model. If I lower it, inflation removes, but there is very little influence from my map at this point, almost as if it is not applied. Substance Painter is essentially not evening reading half the values from the lower end of the map, only the peaks, no valleys.

So, I am wondering what I am doing wrong here? Is it normal practice to be changing the scale, instead of using correct mid values? It feels like I am just missing something all together. Also, how can I subdivide my mesh at render time and control the levels of subdivisions? Any advice would be greatly appreciated. Thanks!

My guess: There is a colour management issue somewhere in the system. To me it sounds like the values have been distorted.

Mike_A
My guess: There is a colour management issue somewhere in the system. To me it sounds like the values have been distorted.

Hi Mike. Thanks for your reply. I have everything mostly working now. I am not sure if there was user error on my part, or perhaps a bug. I deleted the material container and created a new one. This time I started from scratch again, added a subtract node for 0.5 as I would typically do, set the scale to 0.1 and now both Mari and Substance displacement works. Only problem I am having is 32bit 3 channel exr from zbrush, regardless of midpoint at 0 or 0.5, is still ever so slightly inflated. Will have to continue investigating this. Thanks.