VrayFastSSS2 - pre-computed map stops working in network rendering after a while

[Laserschwert]

EDIT: Oh darnit, this was supposed to go into the 3dsmax problems subforum. Can a mod move this? SORRY!

I am rendering an animation which includes an illuminated set of buttons for which I've used backlit objects with VRayFastSSS2 materials on them. Since the buttons are fixed and to save rendering time, I've pre-computed the SSS via the "Save flythrough map" prepass mode. After baking it, I changed the prepass mode to "Load flythrough map" and pick the baked files.

Now, rendering locally works like a charm (at least I've tried it on a single frame here and there), and rendering the animation via backburner renders just a well at first. But after 12 or so frames, the precomputed SSS just switches off, as if it doesn't get loaded anymore, and the buttons in all the further images don't appear "lit" anymore. So I resend the renderjob, picking up from the frame where the SSS didn't work anymore, and again, this time after 20 frames the SSS won't render anymore.

Is the precomputed SSS function somewhat shakey when it comes to network rendering?

Unfortunately I can't send the scene, since we're in the middle of the project right now.

[svetlozar.draganov]

The thread is now moved to the correct section.
Without a scene I don't know what we could suggest here - I'll try to replicate it but if it's something that occurs only under specific conditions it wouldn't be easy to trigger it.

Does it work fine with Single Frame or with RayTraced approach?

[svetlozar.draganov]

I managed to replicate the issue here but not in the same way.

It looks like V-Ray only renders the first frame correctly with Prepass illumination map loaded from file, the rest of the frames are rendered wtihout the map.
This is also already reported into the system but not yet fixed.

It's strange that you have a range of frames calculated properly, that could only happen if each of the frames were calculated on a separate machine.
Is that the case or not?

[Laserschwert]

Unfortunately Single Frame won't work here, because I had to bake SSS for some of the objects separate from the rest of the scene... for example some of the objects are interpenetrating each other, resulting in just black SSS. So I baked some of them separately. My work around now is going to bake the SSS into a Self Illumination texture. Maybe the SSS render element might be useful as a render to texture element as well (it's not available in the render to texture dialogue).

I know it's difficult to troubleshoot without a scene, and I'm sorry about that. Unfortunately we're mid-production.

EDIT: Just saw your reply, I THINK I might have narrowed down the problem. My frame ranges weren't as random as I thought. We have exactly 12 nodes in our farm, and after each node had rendered its first frame from the job, each following frame didn't render the SSS. So somehow the prepass file doesn't get pulled over to the next frame the node starts. So it's independent from which machine has the problem (other wise in the rest of the sequence there would still be correct frames). But it stops working for ALL nodes, once each of them had rendered one frame and advances tothe next frame it gets assigned. So yeah, this pretty much matches your description of the problem.

I hope you guys can find a fix for this!