I'm also having issues w/ Houdini's GGX Surface model matching up w/ Substance's export. At first I thought it had to do w/ linear worklow problems, but that didn't make sense, since all my maps looked correct. I wonder if every other 3D renderer is having this same issue and how people solved it.
Here's what I believe is the problem, Substance Painter does not provide an accurate representation of what you'll see in a mantra render. In Substance Painter as a test, see what happens when you set DIFFUSE to 0. You get black. If you set it to 1, you get white. Fine. But what happens if you do the same thing w/ a Roughness of 0? It is completely incorrect.
Why would a diffuse of 1 and a roughness of 0 look like a mirror? Shouldn't a diffuse of 0 look like a mirror and a diffuse of 1 look like white car paint? (assuming fresnel is working properly).
Think about it, when you add diffuse, you're going away from a mirror reflection. So why in substance painter is it actually making it look more chrome when you add diffuse? See images below for SP vs Houdini renders. I think this is why roughness is not matching up. Because in SP everything looks great, but as soon as you export to Houdini it falls apart.
It is possible that linear maps have something to do w/ this, since in houdini my roughness maps look SUPER reflective even though in Substance Painter they look rough, almost like the sliders aren't matching values 1 to 1.
If you don't know linear workflow here's a beginner's guide:
http://www.pixsim.co.uk/downloads/The_Beginners_Explanation_of_Gamma_Correction_and_Linear_Workflow.pdfHey everyone, just wondering how to get substance painter maps to work in Houdini, tried a number of different ways eg. Principle shader and mantra shader. Can't seem to find info on the subject, keeps directing me to substance plugin but I'm not using designer. Also the render results are less then equal to substance view port.
Please help
Cheers
Brendan