Hi, metal polish values between opengl and cycles doesn’t match that good:
100%:
75%:
50%:
25%:
0%:
They won’t match because of different rendering techniques and shaders used.
I think you miss the point Nathan as a user wants an approximation regardless of technologies that lies behind. As you can see 25% OpenGL looks almost like 75% Cycles so a multiplication formula to simulate the result should be easy to implement. If Cycles output is more accurate than OpenGL I don’t know 
Sidenote: OpenGL results looks like I would expect from Vray.
Comparing with other render engines is a great idea, as both OpenGL and Cycles 50% polish should be as close to the industry standard as possible.
I’ll add a YT item later tonight to get a roughness distribution that is closer to the Rendered mode.
Sounds good but make sure that Rendered mode IS the right benchmark though, as the OpenGL mode has a long history of not being tuned to the render engines. I would at least compare it to Vray and maxwell.
Maybe make a simple demo scene and ask the gurus here to render it with their engine of choise to see how they compare?
Problem is that Rendered mode isn’t physically acurate. And with Cycles posed to replace Rhino Render in the future I don’t think it is too useful to take the OpenGL (rendered) mode as benchmark. Sure we can try to get close with the default materials, but I doubt we’ll get 100% similarity.
I get you, and I think 100% similarity should not be the goal as time is better spent else where, but figuring out how blurry 50% is across the line should benefit both opengl and cycles imo
Yes!
Philip
Here is a simple test I just made.
Vray 1.6:
Cycles Raytrace mode:
it is apparent that you have a similar approach as Vray
I then used the default background in WIP so OpenGL could be compared too:
And OpenGL:
The reflection values are 0, 25, 50, 75 and 100.
So based on this test so far it seems OpenGL needs to adjust it’s settings. If OpenGL’s 50% looked more like it’s current 25% then I think you would hit the spot. I don’t have Maxwell here, nor do I have Arion etc so I can’t test that, but here is the WIP file if anybody want’s to test.
Cycles Render blobs.3dm (9.1 MB)
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Thanks, I will tweak this. YT item: https://mcneel.myjetbrains.com/youtrack/issue/RH-39729
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