Vray "eats" reflections?... :)

[TutanMark]

Hi!!

Yesterday i got a weird problem in an interior scene.

The scene has 2 cameras placed in 2 corners of the same room.. so materials and everything are the same. I have lot of glossy reflections , refractions and vraylights placed everywhere...

Using the 2nd camera.. i got lot of "warning bright.. bla bla bla.. ", and Lightcache invalid samples... and the result is this:

First camera with good reflections!


2nd camera with BAD reflections (please.. look at the ceiling!!!)


I checked .. the most frequent causes of this problem (almost..), like.. bad UVW mapping, light materials, raytraced, ... everything.. and it seems ok...

I don't know if could be a bug... sure is strange..

Any ideas???

Thanks in advance
Regards,
Marco

[marco]

Hi,

are you using the 3dsmax-metal shader for the ceiling?
the metal shader is very tricky to set-up with non-uniform lighting.
a solution would be to give the material a bit of self-illumination...

Marco

[percydaman]

is it possible one of your camera's is using camera correction?

[vlado]

If you are using a camera correction modifier, have you unchecked the "use max-compatible shadecontext" option?

Best regards,
Vlado

[TutanMark]

Thanks for your answers!!

@marco
Thanks!
No, i'm just using Vraymaterials everywhere. The ceiling is a shellac material with 2 vraymat and different reflections .

I have some Multi/sub materials applied to lowpoly characters and plants. All materials inside are vraymaterials

@Percy & Vlado
Hi!...
No, no camera correction.. at all!.. .. Z = 150cm for both cameras/targets.

I will check better again..all uvw maps.. bitmaps are cropped... ..

Marco

[percydaman]

try unchecking the maxshade context button anyways. Also try creating a NEW camera (not clone) and align it to the old camera.

[TutanMark]

I'm trying both...

Thank ya !

Marco

[CCS]

If not any of the above....

Do you have any fallofs in the material? You're at a sharper angle than the other view. Try moving the camera up so that it's angle relative to the camera is similar. If it goes away, you might need to adjust a falloff.

[TutanMark]

Thank for reply
I have many fallofs applied i will try also that.

I have a little update:
"max .. bla bla" is OFF and i created 2 new cameras aligned to old ones... but ..

Lightcache = 1000 subdivision, results is:
Only message with: Warning invalid lightcache samples... itgoes to the irmap calculation and the final rendering.

The image seemes ok... and reflections too!


But if i set...

Lightcache = 2100 subdivision, result is :
many MANY.. "warning... material returned overbright.. bla bla bla..."..

I really don't undestand this difference... and i need (of course) more lightcache subdivisions.

I'm rendering again the "2100" subd solution to see what happens...

Marco

[TutanMark]

Hi

Just stopped the test with 2100 subd, because i got 216 material overbright... .

Regards,
Marco

[jow]

sounds abit like the problems i was getting the other day.
i was testing with 500 subds,all fine but when i jacked it up to 1000 i was getting stacks of material overbright.
and this was on just plane coloured vray mats,also the buckets coming back from the ir calulation where black aswell.
i put it down to photometric lights,as it rendered fine(at 1000 subds) before adding them.
keep us up to date on how it goes,im interested as to what the solution is.i changed my lights to standards and all seems fine but i hav'nt tried with high subds yet.
cheers jow.

[TutanMark]

Oh... this could be an idea.. thanks..

I have lot of Photometric lights inside with IES files applied.. will try to change them to standard.

Let see what happens!!...

Marco

[jow]

ok, ive just rendered my scene at 1000 subds and at 1500 subds and no errors so looks like it was the lights.
hope the same goes for you marco..
cheers jow.

[TutanMark]

Hi jow,

The problem seems related more to some refraction or fallofs... but i'm not sure yet.

Tried also without photometics, but i got errors from camera01, not from the second... I re-checking all... but i dont' have time to render... at high resolution, tomorrow i have my deadline.

Hope to be on my way... anyway thanks for your suggestion

Cheers,
Marco

[vlado]

Something in your scene causes the overbright warnings, the reason you see them only with increased Subdivs is that the problem occurs only for some specific rays - which are generated only after a while. In any case, it is best to find the reason for the overbright warnings and eliminate it.

Best regards,
Vlado