Exponent mapping weird results

Component:YafaRay Core
Category:bug report
Assigned:David Bluecame

Hi there

I am getting weird results with exponent mapping and they have nothing to do with results I expect or get with marmoset toolbag.

Results with YafaRay, white mapping should produce maximun exponent which should mean almost a mirror reflection.

Results with Marmoset Toolbag, glossy roughness mapping. White produces a mirror reflection as expected

You can download scene & texture below and IBL background from


Another issue that bugs me is that untill we formally propose a new way of doing scalar mapping, the new scalar mapping implemented in latest versions should behave consistently respect the existing ones, which means that as noted here, material base value does indeed affects range of the scalar mapping. In sigma mapping and in exponent mapping, base sigma value and base exponent value is not factored for the final result. Either that or we change how the previous scalar mapping works. I think the current system is not user friendly but we must keep consistency till a better solution is implemented IMO. I hope I can propose a new workflow soon based on my experience using Marmoset and Substance. "Default Value" works as expected and consistently with other scalar mapping options.

test1.zip73.42 KB
checker03.png1.83 KB



Assigned to:Anonymous» David Bluecame