Flickering in Alpha with Matte Shadow

[kosso_olli]

Hey,
I have a problem I can't solve. I have an animation of a car here. For the shadows, I used a VrayPlane set as shadow catcher. The scene is lit with a domelight (and two small IES for the license plate). When I play the sequence, the shadow has severe flickering to the left side of the car (it really flickers, it is not video compression). Please see the attached link.
The beauty of the car itself is looking fine, no flickering at all. I have no idea where this is coming from. Rendered with build 3.5.04, full light evaluation. Anybody got a hint?

https://youtu.be/26VquQrl1jI

[vlado]

I'm not entirely sure why this happens without a scene; if you can send it over I will be able to tell you more. I probably don't need the car, just a box in its place, but the HDR map is important.

In any case it would probably work better if you derive the shadow render element manually by dividing the lighting render element by the sum of the lighting and shadow elements:

matteShadow=Inverse(lighting/(lighting+shadow))

Best regards,
Vlado

[kosso_olli]

Okay, will prepare a scene with a box. Thank you!

[kosso_olli]

While preparing the scene I noticed some of the render clients could not reach the used glare image. I made sure that the file is there, yet some of the clients don't have access to it. However, this shouldn't be the root of the problem?
Strangely, the glare image doesn't show up in the asset tracker. It also doesn't get archived by Max's archive system.

[kosso_olli]

File is sent. You have to manually assign the glare image because of the issue described above, the name is test.hdr
It should be enough to render the first 30 frames. Thank you!

[Morbid Angel]

Looks like gi flickering, however I had such flicker in the alpha before with just dome light...

[vlado]

It's not the GI; I'm currently looking into it.

Best regards,
Vlado

[kosso_olli]

Also made a short test with one client to ensure it is not an inconsistency on the render farm. Still flickers on one machine only. Thanks for investigating!

[kosso_olli]

Any news regarding the problem?

[vlado]

No, I haven't managed to resolve it yet.

Best regards,
Vlado

[bennyboy]

I have had a similar problem with using a shadow catcher in animation. Shadow jumps around. I haven't found a resolution yet.

[vlado]

Can you show me? In the original issue, the shadow didn't jump, just the intensity changed.

Best regards,
Vlado