3DArchitecture

I am using Max 7 sp1. With some large scenes I
am getting random black boxes when using Mental Ray.
Is this a bug in max? If not, what is a solution.
See image attached.
Thanks

derijones

It happens with Mental Ray in Maya too. Never got to the bottom of it, but it appears that several people have the problem:
http://forums.cgsociety.org/showthread.php?t=234449
http://www.cgarchitect.com/vb/showth...0034#post80034
http://tinyurl.com/bur3r

Try fiddling with your lighting setup, although they do seem to appear at random (did 4 test renders at 1280x1024, no problems, rendered at 3000x2000 - spots...aaargh!)
Hope it helps
Deri

the white witch

try increasing the depth of your reflection and refration from 6 to something much higher....

abicalho

Are you rendering locally or through the network? Do those dots persist if you re-render or are they random?

Are you using GI, FG? If you lower (or increase) the GI/FG bounces, does that solve it? Does enabling/disabling GI/FG remove the problem too?

__________________
Alex Bicalho
http://www.origamy.com.br/blog

3DArchitecture

Thanks for the help. The black holes are smaller and in some cases gone,
but I still get them in some renderings. It doesn't seem to be tied to any one
setting, rather a combination of settings will help to some degree but not totally eliminate it...esp. in large renderings. What seem to help the most
was limiting the Final Gather radius with lower Sample settings.
I'm still not sure what is causing this??? I've even simply put one material
because it was really showing up with relective surfaces, but this did not elliminate it either... so I will keep testing different variable a post later.

Thanks,

abicalho

What version of MAX are you using, and have you installed the Service Pack available for it?

__________________
Alex Bicalho
http://www.origamy.com.br/blog

3DArchitecture

I'm using 3DS Studio Max 7 with Service Pack 1.

abicalho

Do a quick test. Select all your geometry and apply a UVWMap Modifier, choose Box and give it any size. I know it'll make your scene incorrect, but it's just a test. Render with the same parameters and see if it the black dots are gone.
If they are, then you found the problem. One of the objects in your scene has incorrect UV coords and that object is causing this problem. The solution takes time, and it will be to locate this object.
I'd also suggest contacting Autodesk and entering this as a defect, since it maybe something else.

__________________
Alex Bicalho
http://www.origamy.com.br/blog

nisus

Justy looks like everyone is having the same issues... What does discreet/autodesk/menatl say about this?

nisus

abicalho

Nisus,

I used to, but do not work at Media and Entertainment any longer, so I cannot help you with that problem. You'll have to use the proper channels - through your reseller, through the newsgroups, logging a bug (there's a form in the newsgroup) or by contacting product support directly.

__________________
Alex Bicalho
http://www.origamy.com.br/blog