Cycles & Placeholder, no overwrite & BVH & spatial splits ... Render settings & probs

Hello,

I’m stuck with the correct settings of BVH, cache, spatial splits
as I have had some serious problems with rendering on different machines into a single shared folder with
the no overwrite & placeholders settings, which seems to work fine till now…
I think the BVH settings are the problem, but can’t proof it for shure…
as it takes a lot of time…

In the animation, there are moving/turning meshes everytime, appearing things and so, drivers …
works good on rendering on a single machine…
Sometimes on distributed rendering, meshes are displaced and not animated correct…

I have Dynamic BVH, spatial splits and cache bvh turned on…
Is this a problem for distributed rendering … ?
Are the settings so wrong
I’m stranded :spin:

There’s really no reason to have Dynamic BVH turned on for final rendering, only for viewport preview (if I remember correctly). It also greatly increases BVH build times per frame, plus the added time to write the BVH to the disk. This could definitely cause syncing issues between nodes.

… so: static bvh, no spatial splits, and no bvh cache ?

I’d use static BVH, spatial slits is really dependent on your scene. However, spatial slits are not yet multithreaded so it’s probably best to leave them off. If you have deforming geometry I’d leave cache BVH off or it will be creating a whole new cache for each frame. It’s a rather deprecated setting since BVH building was multithreaded anyway.

We have found that for highly complex scenes… it takes longer to analyze the scene & read the cache off the harddrive then to re-calculate the cache. if enabling spatial splits doesnt blow your bvh build time out of the water, do it, it will enable faster rendering… but if you have trees with leaves… leave it off, it will just take AGES to generate the bvh.

ok, thanks so far, what about “persistent images” is this a problem with distributed render, ?
can anyone write a how2 on the settings which work for rendering on more machines - this would be awesome :wink: