Been exploring Substance Painter for the first time, with particular reference to the new Glossiness in daily builds for 1.5.
Since this is my first time trying this, wanted to post some findings and get some feedback, advice and comments on what I am doing wrong / could do better. Hoping at some point to know enough about what I am doing to make video tutorials about it, if I can understand it better :)
Glossiness
I started with just the Gold Pure material from the Painter Materials library. The only way I got it to work at present was:
- In TextureSet Settings in Painter, set Roughness to Linear (I used L8)
- Use the Converted Maps Glossiness as the output to the Glossiness file
- Save to EXR. If I saved to PNG (even with an RGB value in the TextureSet Settings rather than Linear) then things were not coming out as expected.
If I did the above, then glossiness seems to map 1 to 1 on export from Painter and import into Max, meaning that as best as I could tell the new Glossiness is indeed working to standard. I used high Fresnel values (not importing Fresnel IOR from Painter at the moment, as not sure how that would work) and all was good for materials with a Roughness in Painter of up to about 0.6 (see images for .2 and .5)
However, as Roughness in Painter gets above about 0.6 or thereabouts, the material begins to render more brightly in Corona than it does in Iray or real-time view in Painter (see images for .8).
To correct for that, the Fresnel IOR value in the Corona Material has to reduce, and a reduction of the Reflection brightness is useful too (as at too low a Fresnel value, the Fresnel effect gets more pronounced in Corona than in the Painter material).
I set this up in a crude form - I took the Glossiness EXR, and set a curve so it remains at 1 until a Painter Roughness of 0.6 was reached, then it begins to drop off. With a Corona Mix I used that to multiply with a Corona Colour, and plugged the result of that into the Fresnel IOR so that the value drops with those values of Roughness from 0.6 to 1.0 in Painter. I did the same with the Metal Colour (going into Reflection Colour).
Is there a better way to do any of this? E.g. is there a way to avoid needing EXRs? Is there some better way to control the Fresnel IOR to avoid the overbright results for high roughness values? Is this related in any way to the topic raised elsewhere regarding unexpected results (when compared to other renderers) from Fresnel IOR?
Thanks!
Tom
