Flickering by batch amount

[bender83]

Hi there,

When converting numerous frames in a batch to vrscenes, is there anything different about the way the vrscenes are generated between the first, and subsequent frames? I am getting batch-size dependent shadow flickering and not for the first time. Is it just calculating differentials for subseuent frames?

[Gosho.Genchev]

Hey bender83 ,

In the case of a single VRScene for multiple frames, all geometry, lights, shading nodes and render settings are written for the first frame only. The data for subsequent frames is the difference with the previous frame, if any. For example, if a box was animated at the object level, the first frame will contain all vertices, faces, normals, custom attributes, etc for the box. Subsequent frames will only contain transform information.

Any chance you could send us a scene to check what is going wrong ? If it is sensitive info, feel free to send it to gosho.genchev@chaosgroup.com - the scene will only be used for debugging and will not be shared under any circumstances.

Best regards!

[bender83]

I would love you to take a look but unfortunately it's a massive scene with well over 1000 dependencies - I'm at Zoic, I'll see if I can figure something out. I could possibly send the generated vrscenes and the scene that generated them, but it wouldnt be much use without depedencies :/ Would the vrscenes themselve help?

[Gosho.Genchev]

Hey bender83 ,

If that is permitted, I am also up for a TeamViewer session. Could you drop me an email at gosho.genchev@chaosgroup.com so we can try to think of something ?

Thank you!

[bender83]

I should clarify that I *am* still working in Vray 4.5 because it's a legacy project - would this be something that's potentially been addressed since? I tried migrating my project to H18 and Vray 5 but got crashes (not at all surprising, a LOT going on), so had to stick with what I have.... Does the vray 5 for Houdini beta work with 17.5 per chance? or is it 18.0+ only? That might give me a good starting point to test as such....

[Gosho.Genchev]

Hey bender83 ,

There were a lot of compatibility issues with 17.5 so we decided to limit support to 18.0 and up.

would this be something that's potentially been addressed since?

We had some issues with things changing in animation rendering for subsequent frames but those issues were 1) in V-Ray 5 and 2) not related to the VRScene export (it was correct).

I am getting batch-size dependent shadow flickering and not for the first time.

That would usually be our job but I suppose you could try overriding the materials from the Renderer ROP -> Options -> Materials tab to check if the flickering is present with a default clay material. If it isn't, that would give us a clue. Since it's the shadows that flicker, it very well could be something related to the lights. You could try using the Renderer -> Objects tab to disable all lights except for e.g. a Dome Light to see if the flickering is still present.

Hope that helps!

[bender83]

Just a quick update:

I've been breaking this scene down to get the smallest possible repro I can get for you - it is flickering shadows, however - flickering DOES seem to stop with simple grey vrayMtl applied to all objects.