Animation and "Time dependant" glossy noise problem

[xtrude]

Hi all,

I'm coming across a problem in my animation project. I guess I'm not the only one who had problems with noise and animation, and I'm sorry if this issue has already been discussed many times, but I just can't find any solution in all the threads I've been reading.

My situation : I'm using IrMap/LC and since I have moving objects, I calculate my GI in "single frame mode". I've been playing with different quality parameters, BUT I still have the same problem : I've a subject that's a product with many glossy reflections (stored in the LC btw), and although the noise is very pleasing on stills, it behaves very weirdly in animation :
- with the "time dependant" on in my DMC sampler settings, lighting is uniform in the animation BUT noise is fixed in the image and looks like it's sliding upwards as the camera moves. That's quite undesirable.
- with the "time dependant" off in the DMC settings, noise is better : changing pattern in every frame, it doesn't "swim away" anymore, as the camera is moving. BUT lighting is "flickering", i.e. flashes happen in many frames, or i could rephrase it like that : lighting is not uniform throughout the animation, which is very undesirable.

This is a great problem for me : None of these solutions is satisfying. I'm sure you already have come across this problem if you make animations with vray.

Thanks in advance for your help.

Xtrude

[LarsSonparsson]

Are you using "store direct light" option in lc?
That has caused flashes/flickering in my renders many times.

-LarsSon

[xtrude]

Hi LarsSon,

Yes indeed. That could be the flash/flicker explanation. Thanks.
Now remains the time dependant "noise swim" problem... I probably could get rid of it by un-ticking the time dependant feature, unticking the "store direct light" and take care of my noise levels.
I'll try this and post results. I simply hope it won't lengthen my render times too much.

Thanks again for your idea.

xtrude

[LarsSonparsson]

I haven't found it as a render time killer. If you have large area lights and shadows looks noisy, you could easily increase the lights sampling
level to 16-24 or so. That way you don't have to boost image sampling levels too high.

I'm always unticking time dependent. For me, it's much more acceptable to have some noise/grain than that "noise swim" problem.
I think that most of the people are ok with some noise anyway. Sometimes, when it's subtle, it just looks natural like film grain.

-LarsSon