OSPray pathtracer: erratic walls

When batch-rendering transient data for video production using the OSPray pathtracer I frequently observe erroneous walls popping up.

These are most often (but not always) aligned with the xy, the yz, or the xz-plane and would then have the only one visible corner at the origin. They appear pitch black or partially translucent.

Is there any knowledge, what I can do to avoid this issue?

Background:
I am batch-rendering data-heavy transient scenes. In order to reduce the time spent reading data my state files usually have multiple layouts each holding a render view. These render views visualize the same data in different ways.
My paraview sessions then iterates through the time steps, and for each time step iterates through the render views, producing a png file for each view per time step.

FYI @Francois_Mazen @timothee.chabat

Can you share a picture with the erroneous walls in it? I’m hoping it will help us to identify the specific problematic code path. Thanks.

I was a bit fast at deleting the unwanted images, but here is one example:

I think that one corner is always at the origin (0,0,0).

This looks like the same issue to me:

I also think this is the same issue. I couldn’t looked into it so far but I’ll keep you updated if I discover something along the way!