PDA

View Full Version : Black Dots


psyny
05-24-2010, 10:31 PM
Hello,

My problem is quite simple to describle... Why there are black dots in this image?
http://img.photobucket.com/albums/v635/Psyny/CG/BlackDots.jpg

Iam using Mental Ray for renderer and Mia_Material for the "water". Ive used it before and no problems =/

The problem appears when i add transparency to the Mia_Material. More the transparency more visible are the black dots.

Edit1:
The problem is the ground i think. Changed ground ( the beach ) texture and it was ok again.
But i need that ground, still need help.

petey
05-25-2010, 12:25 AM
Looks as if it might be something to do with the number of samples. I haven't played with those materials much but you might want to see if you can up the sample rate or something.

Someone else will probably have a better answer :)

TaKIKO
05-25-2010, 12:33 AM
Does the ground have a blinn or a maya shader on it?

psyny
05-25-2010, 03:16 AM
Thanks for the replies.

Number of samples? Raytrace samples? Just tested to increase from 2 to 20 and nothing changed.

Yes, the ground was a blinn shader. Changed to Mia_Material, redid the network links and the problem persists the same.

Just figured that is the BUMP who cause the issue. Will test in other scenes soon.
But even with a BUMP of 0.01 the dots pops up. However, changing the bump to 0.0 or removing it get rid of the black dots...

TaKIKO
05-25-2010, 02:09 PM
I had the same problem:

http://forums.cgsociety.org/showthread.php?t=785386

In the end I ended up just taking off the bump on the planks in the back but it was all covered with dof anyways so it didnt matter(Link (http://michaellampe.org/3D/images/cigarStill.jpg)). I did have a friend who told me that refraction with a mia and a blinn with a bump was a bug and switching to all MR shaders fixed the problem.

psyny
05-25-2010, 10:18 PM
I had the same problem:

http://forums.cgsociety.org/showthread.php?t=785386

In the end I ended up just taking off the bump on the planks in the back but it was all covered with dof anyways so it didnt matter(Link (http://michaellampe.org/3D/images/cigarStill.jpg)). I did have a friend who told me that refraction with a mia and a blinn with a bump was a bug and switching to all MR shaders fixed the problem.

I've failed to reproduce the bug in another scene... But its ok, like you said, i just removed the bump from the scene underwater and the black dots are gone.

http://img.photobucket.com/albums/v635/Psyny/CG/Render_02_Beach.jpg

And thanks to this forum its my first scene in Maya =)
Crap work, hehehe. Lets start again...

Edit:
Someone can give some tips in this scene? Like why the ocean far away dont look well or at some places the reflections distorts a bit too much.

CGTalk Moderation
05-25-2010, 10:18 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.