Vray Curvature Flicker

[shegmann]

Hello all,

We have been attempting to use the VRayCurvature as a Blend Amount mask in a few different materials now. This particular material is a VrayBlend with a Base of a worn type of plastic, a coat with the curvature blend of a more worn plastic to make the edges appear older, and then a second coat with a blend mixing a VrayDirt and solid fractal for a dirty look. I attached the nodes just in case.

The issue, as you can see, is that the curvature texture seems to be flickering between frames. We encountered this on another model with a completely separate material as well. It seems to be happening when objects with another curvature are close in proximity to the first? We're not entirely sure. But you can see the upper portion of the desk is stable while the inner portion is going kinda crazy. This was also observed in the firetruck we had previously, where the curvature flickered only on a particular door that had closely placed slats. Now, two models aren't a pattern but they are enough to make us suspicious. Is this something that has been run into before? We didn't spot anything on a quick search through the forums but it was not a super in-depth one, I'll admit. I'll be testing this by applying a material on the bottom piece that doesn't have the curvature coat applied, but it would be great to know if this is something that has been encountered previously. And, if so, if it's something that has an easy (or at least doable) fix.

Many thanks!

[dgruwier]

I've run into it too, but didn't have time to troubleshoot or report it at the time, I just baked the curvature map as a texture and forgot about it. I'll keep an eye on this thread. I was also using a texture to drive the sample spread.

[vlado]

If you can get us a scene for this to support@chaosgroup.com it will be very helpful. Other than that, try turning off the "Animated noise pattern" option in the "DMC sampler" rollout. But we have to fix it anyway, so if we get a scene that reproduces it, it will really help a lot.

Best regards,
Vlado

[shegmann]

Hi vlado,

Sorry for the delayed response, I have sent over the scene to the support team as you suggested. It is also linked below. As I wrote to them, this is a much slimmed down version of the scene that we haven't tested. The flicker occurs on the control desk itself, with the material Control_VRayBlendMtl (with name spaces it came in with TXC_ControlRoom_Layout:ControlDesk_TXc:Control_VRa yBlendMtl after importing all the models from references). We also placed the flicker version onto a placeholder sphere so it's easy to find.

The fix we came up with was to put a version of that material that didn't have the curvature applied to it on the bottom portion of the desk. This meant that there weren't two objects with the curvature applied right next to each other. When we did that, the curvature on the top portion of the desk remained stable.

We removed a lot of items and stuff because once archived it was over 3GB with a metric crap ton (technical term) of materials.... and we felt that might have been a tad too much to send over. So this is the reduced version (with the same camera move that the original had, even though the figure has been removed). The archive is a zip file.

[yolov]

There's a duplicate object where the flicker happens, so it might be what's causing it.

[shegmann]

Ah, yes, I see that now. Thank you for catching that. It is possible that is contributing to the issue. We will definitely remove that and test further.

However, neither panel is flickering where the duplicate object is and the neighboring panel is also flickering on the bottom. And there is no duplicate there. In addition, this is the same problem as we were having on a completely separate mode that also had closely placed objects with a curvature on it (a fire truck). We appreciate you looking into the issue!

[yolov]

Then it's worth a second go-over from our side. Thanks for the input.

[nikolay.kusht]

After further investigation, it seems that the VRayCurvature is producing some flickering when rendering with the GPU engine. This issue was reported as a bug(VGPU-4410) to our system. We will inform you when we have progress on it.