3ds max+Vray Flickering high light

[Anonymous]

Hello,

Difficult and laborious stage of rendering, where the working hours now take a few presets.
Despite my research on the internet, I am asking your help.
I do indeed have flickering in the highlights. as you can see in the video.

I'm on the Vray 5 version (similar to previous)
Image sampler: Bucket
Brut force
Light cache, preset animation, mode: From file
Default settings.

I export .exr and apply the denoiser tool
I tried BF+BF, IM+LC : it didn't work either

Is it a problem of antialiasing, of subdivisions, of rendering engine settings?

Best regards
Denis

[Francisco_Penaloza]

First, on the Ligh Cache are you checking the camera path checkbox?? you should.

Also, in the latest V Ray, actually, since V Ray 3.x there is no need to pre-save Light Cache for quality purpose. You can give high value, such 2000 or 3000, and just let the render nodes rip, of course, it will take a little longer per frame but there will not be any GI flickering.

Having said that, Flickering may happen for many reasons, Usually is geometry, Shading, GI.

First Check the thin part of those arched beams. Check for Polygon orientation and any overlapping geometry.

Are you using Dirt shader?? if so you need to reduce the radius so it is not larger than the thinnest geometry?

Thirds I see some major Frames noise every 50 or something. Check that Light Cache has the camera path checked. You can use the Sample rate pass to see where the noise is coming from, you can lower your Noise threshold.

I don't think is the high light as a clamping issue. I am more inclined to shader issue or mesh. But I would need more info to debug correctly.

Review what I told you and let us know.

Cheers.

[Anonymous]

Thinks @Francisco_Penaloza 

for your answer which gives me hope to find a solution.

In Vray 5 the camera path has disappeared, replace by the preset "Animation" (attached the screenshot)

I use a Vray dirt (radius=8) and VrayEdgeText(Radius=0,3) I will test without and no Shader

About the geometrie, I started a few months ago, modeling with Rhino,
I have surely made mistakes and would be unable to correct them for the moment.

I join you, my sample rate pass, he looks bad

Thank you for all these tracks that I will be working on
Best regards
Denis

[Anonymous]

Hello @Francisco.Penaloza 

I come back to having done a lot of testing.

You were absolutely right about my mesh.
I started from scratch, and re-imported my .dwg Create originally in Rhino 3D.
(it is not excluded that this mesh has no problem) Are there checking tools?

As you will see in the video: without_flick.mp4
the rendering is good, I felt relieved.

I tried on another sequence: Trav_denoise_flick.mp4 and there are some issues.
it reminds me of the 3ds preview that I am attaching Trav2_preview3ds.mp4

I wonder if it's a rendering problem or an animation problem?
As you can see the pillars of the fund seem to be shaking.
The one in the foreground, shifting faster, scrolls jerky.

What do you think ?
1) increase antialiasing.

Bucket, Min Shading rale: 6
Min sub 1, max sub 100
Noise thereshold: 100
(I read that it wasn't much use to exceed 24, possibly 32)
Image Filter -VrayLanczosfilter, size: 2
Primary: Brut Force
Secondery: LC
Preset animation
Sub: 3000
Sample size 0.01 retrace 8

2) Slow down the sequence shot

Looking forward to reading you
Best regards

[Anonymous]

Hello, it doesn't make sense, this morning I launched the preview of 3ds max set to maximum quality (100), the result is almost excellent (no flickering or jerking) How is this transposed in Vray?

Beautiful day

Denis

[Francisco_Penaloza]

Hello,

If I understand correctly your question, 3D Max screen preview doesn't have any relation about output quality with any raytracing rendering engine. Maybe the latest version of 3D Max may 'display' closer shaders colors to what you get with Arnold but when is animation the flickering or antialiasing is totally different.

Preview is just to get an idea of timing with objects and camera, nothing else.

When you render that's is different.

regarding your animation, first, your scene is hard to resolve for any raytracer, because you have very intense lights and very dark colors, these two will give hardtime to the process of antialissing, whit work at the sub pixel level using contrast values.

Having said that, default V-Ray setting should work fine. your setting seems OK, but your Noise threshold should be smaller, much smaller, around 0.01 or less.

Bad geometry will give problem in animations, no matter where is modeled, you always need to check for intersecting geometry, or two faces in the same plane, backward, or flipped polygons (inverted normals) and if you use anything such Dirt, or Glow, or subsurface shaders, you need to check for very thin geometry or anything that I mentioned above, because that will give you errors.

Please review the Help doc of V-Ray, in there you'll find a deep explanation of what the settings do and how to use them.

There is not a setting that works for everything and all. But the default give you a very good start most of the time.