Imap vs. BruteForce Rendertime issue

[Vitro]

Hey guys...

I spent weeks now on trying to get a flickerless scene. First I decided to use only the Light cache engine for both primary and second in addition with an ambient Occlusion pass.
It was absolutely ok fo that kind of job. But I could not get flickerless light cache. So I switched to Imap and light cache..using the pre-render and animation process.
But also there I could get rid of the flicker only with very high settings and interp. frames like 10 which then gave me rendertime as long as brute force itself.
Now how can this be?? It doesn't have to calculate neither the LC nor the Imap, yet it takes as long as brute force.

My scene is basically one character. And the flicker appears to be only very strong on his face, if not only, which confuse me too.

I had a look on my Imap within the Imap viewer. The samples on the character look good to me. Around him are some hudge points though..out of camera though..so maybe its supposed to be like that.

I am new to Vray and I dont quite understand yet.

cheers

Vito

[vlado]

Can you show a few frames from the animation? Or send them to vray@chaosgroup.com?

Best regards,
Vlado

[MHolmstrom]

the flicker appears to be only very strong on his face, if not only, which confuse me too.

Are you using a FastSSS-material or interpolated reflections/refractions?

[Vitro]

Are you using a FastSSS-material or interpolated reflections/refractions?

in fact i am.... I find out last night that interpolate reflaction cause bad flicker in animation...but SSS2 as well? How to solve it?

[MHolmstrom]

Set the prepass rate for FastSSS2 to 0 or higher

[Vitro]

Set the prepass rate for FastSSS2 to 0 or higher

no that doesn't help...I already set it to 2 ^^

[vlado]

I remember that someone reported flickering when using the VRaySun together with the sss2 shader, which was solved by reducing the sun intensity; in any case - getting us a scene to debug will be very helpful.

Best regards,
Vlado