Black squares on rendered image??

[dlparisi]

I'm having a weird problem getting black squares over the rendering. They look similar to a overlapping face but I've double checked the file and can't find anything else at that location (it actually happens in a few other portions of the image as well but I'm showing this as a sample). I recently upgraded from Viz2005 to Max9 but this never happened in VIZ before.

Here's what they look like (at the top of what will be the stone base):


The model is modeled in AutoCAD and linked to Max9. Lighitng is via Vraysun through a vray camera with exposure on (doen't matter though).

Here's what I've tried so far to fix it:

• -set the 2nd ray bias to .01/.001
  -using a normal camera
  -using a normal direct light
  -changing the vray sun shadow bias to 1 and 10
  -changing the color mapping settings to subpixel/clamp
  -turning off all GI

If I isolate the base course and just render it, it's OK. If I hide the base course and render there doesn't appear to be any other geometry there.

Also, if I move the base course back a little (about an inch) the black square starts to shrink like this:


If I move it an inch further it disappears altogether:


It also renders fine in scanline with a direct light and normal camera.

Any ideas? Could this be a bug with the linking in Max9?

[vlado]

This is a problem with RC3 specifically in 3dsmax 9 that happens rarely; it is fixed already; if you want an update, please email me to vlado@chaosgroup.com

Best regards,
Vlado

[dlparisi]

Emailing you now...

I'm curious though, can you explain a little bit of what was going on/what the problem was? This one drove me batty for a couple of hours until I gave up on it .

[vlado]

It happened because of some precision loss when doing the ray-geometry intersections.

Best regards,
Vlado

[dlparisi]

Of course! That's what I thought the problem was! (I had a feeling it would be some explanation like this, serves me right for asking). The update fixed it right up.
Thanks.

[ern]

Hi Vlado & dlparisi

I have the same problem.... I think!

@vlado: I have sent you an email, with a picture that shows the problem.

@dlparisi: did the update fix the problem?

Regards

ern

[dlparisi]

The update fixed it right up.