Flickering on reflections VRAY 3.7

[pixilab]

Hi there,

Sorry to bother most of the people with an old problem on an old version of Vray for C4D, but the transition takes time and I still have to use 3.7 for some (most) project..

Basically I get flickers on my reflections, I'm pretty sure it's not due to the geometry but mostly regarding the GI settings I have.
I'm looking for the best combination of setting, knowing I can't put them too high because of the render time. For the moment, with these settings, I get some flickers and I have to solve that problem in post.

It's not the best solution and I'm trying to improve it since a few weeks now, I find hard to have the best combination to reduce the flickers, I've been told it's a combination of subdivisions in the light cache and retrace threshold, normally I should go higher about 3000 in subdiv and 8 on the threshold, but If I do that my render time just double... You have a printscreen of my setting just there.

Thank you for your lights guys.

Cheers,
Arnaud

[pixilab]

Sirio, any ideas?

[sirio76]

I’m not sure GI settings are the problem, if the flickering occur only on reflection the issue is probably somewhere else. If you upload a small sample of the video it will be easier to understand what’s going on.

[pixilab]

Here is a portion showing clearly the flickering
It's the inside of a machine, so there is a lot of relfective elements in metal (almost only that)

[sirio76]

I’m not sure what is the cause of the flickering but it doesn’t look like is GI related. Check your geometry to be 100% sure you do not have overlapping complanar faces.

[YunalZobu]

On the flat part really looks like a "double geo" issue and on the revolving circular part I see a triangulation issue due some "boolean" like cut.
Can't say for sure without a scene, but it really seems like a poly issue, happy to take a look tho, if you can share it

[pixilab]

Thanks guys!

Here is few geometries of the machine, as it's from the CAD world there is a lot of triangles everywhere, but no double geometry

[YunalZobu]

Just opened the scene and ran a Mesh Check, quite a few not planar polys there. I'd either try to export it once more from the CAD software with different settings or run a Triangulate on it in c4d.

[pixilab]

Thank you YunalZobu, this analyze help me to locate the issue. I'll check if a triangulate operation will make it.

[YunalZobu]

Happy to help, share a final image/sequence when you can