Stumped: Flicker in cell animation, using Animated IR + Brute force

[jpl1040]

So far I've been able to get good non flickering results with the prepass/render mode of animated irradiance maps. But this job just won't render without what looks like 30 fps flicker. Not sure how it's getting in there but I thought I'd see if you had any ideas.

Here's the movie file - 200 KB WMV movie

http://www.trinity3d.com/FTP/cellFlickerTest.wmv

The flicker is subtle and in the background.

I thought using Brute Force for secondary GI would be the best bet in this case. But we've tried it with precalc'd "fly through" light cache and still got the problem.

Can someone with some experience with complex animated GI in VRay offer a tip?

thanks,

Jim

[khoross]

it looks like the flickering is caused by a GI problem

ur settings might be too low. Hsph subdivision 50
interp. sample 40

i think u should decrease ur interp sample or increase ur Hsph subdivision.
i usually try to keep them in the same ratio ex (50/20....100/40....150/60)

[jpl1040]

Our earlier tests were at 50/20 and I increased it to 40 to try to help it smooth the shading more.

But, wouldn't any flicker be smoothed anyway by using animated IR? The IR CAN'T flicker at 30 fps, because it is set to blur 5 surrounding frames of IR together... any flicker caused by IR should be slowly smearing, not boiling. Right?

it looks like the flickering is caused by a GI problem

ur settings might be too low. Hsph subdivision 50
interp. sample 40

i think u should decrease ur interp sample or increase ur Hsph subdivision.
i usually try to keep them in the same ratio ex (50/20....100/40....150/60)

[khoross]

its difficult to predicted whats the problem in ur scene ,
im guessing ur using vraylight with store to irradiance map option.

vray image sampler set to adaptive subdivision. with adaptive dmc u get more details & more predictable results ,i personaly use it all the time.

have u tried any other settings ? IM & LC with adaptive DMC , try lowering ur blur with surrounding frames.

[jacksc02]

How are you lighting the scene?

[jpl1040]

How are you lighting the scene?

It's a bunch of VRay area lights.

[EricKlein]

Have you tried per frame LC for your secondary with very high settings? like 3k? (with irr map animation mode)

e.

[sv]

or you could switch to Brute force primary with LC secondary?
Turn off the 'store direct light' in the Light Cache and set it to single frame mode....

and play with the DMC AA sampler to set the quality - try 1/8 @ 0.003 and keep going to something like 1/28 @ 0.001 if it's too noisy....for quick tests try 1/2 @ 0.1

[jpl1040]

I think I may have the culprit - analyzing the scene, the scene size (we didn't build it!) is like 150' square. So are the area lights. I think they are all just way too big to work reliably when the finished look is supposed to be this tiny thing. We're testing it again with the scene resized, and I'll let you know if that fixes the flicker.

thanks

Jim