Lightcache calculation very slow

[metroberlin]

Normally LC calculates very fast. Especially with RC4 it seems to be even faster. I have now a scene where LC is extremly slow and I can´t see any thing which makes the scene different from others. Indeed, there are quite a few area lights in the scene, but even without these lights it´s terrible slow. This speed def. would kill us later in the Animation.
Are there general points which can effect the LC speef ? Size of the scene, wrong dimension, too much glossy material ....something ? any ideas ?

thanks

[instinct]

a Shot in the dark :

# Do not set the Adaptation by importance amount in the QMC sampler rollup to 0.0 when using the light cache, as this will cause excessive render times.
# Do not apply perfectly white or very close to white materials to a majority of the objects in the scene, as this will cause excessive render times. This is because the amount of reflected light in the scene will decrease very gradually and the light cache will have to trace longer paths. Also avoid materials that have one of their RGB components set to maximum (255) or above.

(from the manual)

Thorsten

[vlado]

Also, if you are rendering a high resolution, turn off the Show Calc Phase option.

Best regards,
Vlado

[metroberlin]

thanks for input so far...will test these suggestions...

[priad]

let us know the end.

[vlado]

Ah, and if you are using 3d displacement, make sure you increase its Edge length parameter.

Best regards,
Vlado

[metroberlin]

in the end it a problem with double faces of some models. and also i scaled some vray lights and this is obviously also not that great

[gfree]

[..] and also i scaled some vray lights and this is obviously also not that great

Is this true? I scale them quite often.

[greg04]

well, as far as LC is concerned, i abandoned the idea of using it in an animation where i have a visibility track set to anything in my scene, LC calculations take zillions millions hours. I just had to go ahead and do the animation in scan line /time issue / which a shame. the same animation using QMC/LC and no visibility track goes with no problems.
any ideas?

[DaForce]

vray will crap itself if you have an animated visibility track. Well you can go from 0 to 1 in a frame, but if its anything more than that you will ahve problems.

[metroberlin]

i don´t know 100% if the scaled lights caused the issue...but once i replaced them it was okay again

[kimgar]

vray will crap itself if you have an animated visibility track. Well you can go from 0 to 1 in a frame, but if its anything more than that you will ahve problems.

what would be the best way to make vray not crap itself when fading objects in and out?
we're mass producing these kind of animations - with new workstations and all, there is finally room for vray in the tight deadlines, but not all the comping involved in the premiere way...

[kimgar]

nevermind, i just found this topic

http://www.chaosgroup.com/forum/phpB...ght=visibility

although, some vray visibility option would be great