spots, spotches, color splashes, random render problems

[andrewjohn81]

Why can't I find some help with these problems in the chaos forums. I found some help on metinseven.com this time around.


I have a vray material that is slightly transparent with blurry reflections and blurry refractions. The material is also colored.

Appearantly having the material colored in this way lends a huge almost random problem with irradiance maps?

I can not find a solution to fixing this problem. Certain frames always render bad with horrid green splotches. Sometimes it's the entire scene that is green. The ceiling is dark. The green problem areas are also visible in reflections, which is something i haven't seen before.

It is most definitely a problem with irradiance map. The problem is, since I didn't see a problem before I rendered the large frames and sent them off to be printed. The animation must match.

Any suggestions?

[Candelero]

Can you show some images please.
Also which V-Ray version are you using, MAX / VIZ ?

Best regards,
nikki Candelero

[andrewjohn81]

Sorry that took some time there. I opened up a tripod account. i have webspace but whirlpool blocked ftp access and also blocked my webtool for uploading things to it. IT Jerks!






Sorry that's long. I didn't want to miss out on any small details.

One is fine....well, acceptable at least. Any problems in that one are pretty much just the quality settings. Any higher of settings seems to make the rendertime triple. I played around with it a bit, but settled for that for now.

I am using Max SP2 with VRay Adv 1.47.03 That's the most current right? I thought so at least. Please let me know if I should have a new one. I would assume they would email us about any updates.

i tried several things. I tried changing tons of settins in the irradiance map settings, but got no real changes there. I tried making the glass completely transparent. I tried replacing the diffuse color to a fog color (although if that works then it just seems like it's a bug or something).

I'm at a loss here. i'm hoping at least one of you can help.

[ene.xis]

the last one is mind blowing!!

i would sugest it to be refraction value related...?but if it s not...maybe geometry?
i´m out of clues!

[andrewjohn81]

I'll give you a clue.

I think I just figured it out.

Shadows. I've heard that shadow maps don't work....not in use here by the way.

i unchecked affect shadows for the material in question (the material on the glass fronts) and it worked fine.



Sounds like a bug to me

[dimo]

Hi,

If it is shadow map related try to move the lights slightly, so that the plane is not coplanar to the light direction any more. This worked for me once.

Best Regards,

Dieter

[ene.xis]

glad u sort that out...
but u got me confused...

....not in use here by the way.

r u using shadow map or not?
...and why?i still find hard to understand why people still stik to those stuff raytraced materials, shadow maps...?
anyway i m glad ur on the way now!

[andrewjohn81]

I'm semi on my way.

I've turned back on the affect alpha and shadows and it works fine.

All i did was turn it off, render, then turn it on again and it's fine.


No, I am not using shadow maps. I just saw that someone mentioned there were problems with them. I am also using no raytraced materials. I am using one standard material but I have it going through the material wrapper just to ensure that it doesn't have problems with GI.

[ene.xis]

I am using one standard material but I have it going through the material wrapper just to ensure that it doesn't have problems with GI.

why??
how come can t u just use a vray mat?easy fix...
and about ur solution....i am afraid it might not be a permanent one...
i rekon there s some major conflit in that scene...

what about strange error messages in the vray messages window?

[andrewjohn81]

ok, I didn't have the vray messages up. We almost ALWAYS get the warning: Material returned overbright or invalid color (object "xxxxxx", RGB: -1.#ND -1.#ND -1.#ND)

of course each warning has an actual object name.

This does sound right, but why would the scene work at all? That doesn't make sense to me. Why one frame and not another? There isn't anything moving but the camera.

Most everything we do comes from ProE, or had at one point or another been in there, so there are almost always coplanar surfaces, or surfaces that are about .001 inches close to eachother.

Often times I am aware of them and move them ever so slightly apart. Does anyone have another suggestion? It can't be to remodel things because it would be impossible.


Why turning off affect shadows worked before I don't know, but it worked for two frames. I'm doing one that was pretty much all green and it isn't working. I'll post any progress, but it's slow going for now. I can at least tel if it's going to mess up by previewing the irradiance map using Show calc. phase. If it's black it renders green.

[andrewjohn81]

RErender semi-answered my question in another psot I think.

I'm rendering now with only 75 Light Cache samples instead of the previous 500. I tried 450 initially and it seemed to look better, but still had some ugly black spots in the irradiance preview, so I knew it wouldn't work. I am rendering now with only 75 and the IR preview looks just like the other ones did.

The rendering is finishing up now, and although at the edges it doesn't look as good, there are no errors.

Why, oh Why is this listed nowhere????

I've been working on this for hours. Thank you RErender wherever you are.

I would much much rather have the full quality, but I should be able to rerender these frames at this lower quality and it won't flicker Too badly.


Any added help guys?

[andrewjohn81]

I have yet More information reguarding this issue. I'm hoping a vlado or someone else from chaos will jump in here and help out at this point. There seems to be no sense to this problem. Why certain frames and not others is the main thing.

If I change the Sample size to super small, .001 in this case, for the light cache the overbright warnings nearly disappear. I still have 500 subdivisions, but only have one smalle green dot. But, of course, now I have a bunch of little dots All over my image. That's just Not going to work.

So changing to smaller sample sizes seems to help, but having higher subdivisions makes it worse.

Is there any list for this issue that tells what effects it how? I searched the forum for "overbright" and there are Tons of extremely similar issues. Most of which didn't seem to be resolved.

[Da_elf]

maybe its that bug dark square that says "sorry, cant show this" thats messing up the render?

[studioDIM]

Lol da_elf!

AndrewJohn, did you try cropping your bitmaps, as per this sticky post?

http://www.chaosgroup.com/forum/phpB...pic.php?t=9604

reRender prepared a nice script for it...

Lele

[ene.xis]

i really don t think ur green spots to be Lc related...
but then again i might be wrong...and Da_elf might be right...hehe


i would bet on that wraper mat or the glossyness in the refraction...