Cycles vs opengl metal polish


Hi, metal polish values between opengl and cycles doesn’t match that good:






(Nathan 'jesterKing' Letwory) #2

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 :slight_smile:


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.

(Nathan 'jesterKing' Letwory) #6

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?

(Nathan 'jesterKing' Letwory) #8

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 :slight_smile:





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)

(David Eränen) #12

Thanks, I will tweak this. YT item: