higher light cache samples couse dark renders

[gilicom]

Please help
I'm rendering an image on very low settings to check the lightning (100 sub on lc and very low preset on irr map) and every thing looks fine.
i then try to render a better image using 1000 sub on lc and medium on irr map and the render turn out all black + i get all kind of "metirial returnd over bright or invalid color" from many objects.
It is strange because all my mats are vray mats and all of these warnings didn't showed up when my lc settings were low.
did it happend to somone?

[flipside]

That is possible because with your low settings, vray doesn't detect these overbright samples probably.

Tell us a bit more about your scene, maybe post an image if you can. Could be modeling issues.

[gilicom]

Thanks flipside
I will post the render as soon as the good render will finish rendering.

[chris-x//]

I have the exactly same problem right now,

Irr map -3 -1
.3 .22 .4
50/20

LC : fixed, prefilter 10

Lightcache : 1000 samples >> black render, almost every object returns an overbright error

Lightcache : 200 samples >> All is ok

I've done like that in 3 scenes today, no problem and the last one BAOUM
Damn why always at the end of the day.....

[jow]

i had same thing a couple of weeks ago,photometric lights turned out to be the source of the problem...
cheers.

[jacksc02]

Chris, try reducing your LC samples to 800 and see what that does.

[gilicom]

well here they are i hope vlado or somone from chaos can tell us how to fix this
good render (lc 200) ir = -4,-4

bad render (lc 1000) ir = -3,-1

[flipside]

Did you try the 800 subdivs as suggested by jacks02? I remember reading something about the evil number 1000.

[chris-x//]

Exactly what i get when lightcache is above 1000, i tried 2000 for final render... have to try 800, but 500 worked... strange

[gilicom]

will try 800 but i think its some kind of bug and it would realy help if vlado will help us on this case

[flipside]

It could be a bug, but probably related to something you're using in your scene. I use subdivs=1000 and also higher all the time, without any problems.

Simply send your scene over to vlado if you want him to find it.

Try hiding objects one by one, untill the problem dissappears.

[gilicom]

will send that scene to vlado but i went through it and find nothing
all of the mats are vray mats, and i've doen a lot of scens exectly this way and used higher lc and this is the first time its happend

[jacksc02]

try turning off your refractive curtains and see if you can do 1000 subs

[gilicom]

just tried to render the same scene with lc - 1000 and could not get the black render again, everything was fine .
didn't changed anything from last time...
so now I realy don't know what it was.