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UniqueCharacter
06-28-2009, 09:16 PM
Hello, I need some help with mental ray. I'm using Maya 2008, and the shader on the watch is just a Mia material with the chrome preset. I believe the artifacts are refractions, but I don't see any way to enhance the refraction samples. I tried upping the reflection samples to experiment, but no help. I'm rendering with the preview final gather preset. I suppose I can up the samples in rendering, but I'd like to see if there is another reason. Thanks for your help.

techmage
06-28-2009, 10:58 PM
actually It's kinda hard to tell what that is from your pic. What would that be refracting through? They look like shadow samples to me.

Turn off final gather. See if it goes away
If not, turn off each light individually, to see if it is caused by one of your lights.

MAV4d
06-29-2009, 12:19 AM
did you freeze your FG map and move the camera? thats what it looks like

UniqueCharacter
06-29-2009, 12:37 AM
rygoody: Yes it does look like a shadow, but it's not. There isn't anything in the scene but the watch and the light isn't even pointed at that angle, that's why I am thinking it is a refraction from the chrome. The ground is just a plain o' lambert. I will attempt to try the things you suggested and get back to you.

Mav: no... I canceled the render when I saw the artifact.

anevsky
06-29-2009, 01:32 AM
Its very hard to tell from that image - post your scene / screenshot / at least 1 normal frame.

since it looks like a shadow from nowhere - 1. replace the lambert with mentalray shader.
2. make sure all your meshes are set to drop shadow 3. forgot what 3 was supposed to be.

MAV4d
06-29-2009, 01:54 AM
rygoody: Yes it does look like a shadow, but it's not. There isn't anything in the scene but the watch and the light isn't even pointed at that angle, that's why I am thinking it is a refraction from the chrome. The ground is just a plain o' lambert. I will attempt to try the things you suggested and get back to you.

Mav: no... I canceled the render when I saw the artifact.


in the mr render setting tabs, there a way to freeze fg the fg map.

it will only cast once, from a previous camera location...

so area behind objects do not receive fg cast, which makes it look odd.

techmage
06-29-2009, 02:10 AM
rygoody: Yes it does look like a shadow, but it's not. There isn't anything in the scene but the watch and the light isn't even pointed at that angle, that's why I am thinking it is a refraction from the chrome. The ground is just a plain o' lambert. I will attempt to try the things you suggested and get back to you.

Mav: no... I canceled the render when I saw the artifact.

still. Turn off FG, then go through and turn off each light individually just to check so you can rule out any problem with the lights.

UniqueCharacter
06-29-2009, 02:14 AM
Mav: Sound's pretty complex, not sure about that. Do you mean some kind of baking?

Ry: Thanks for your help buddy. It was the lights like you said. I was using a preset I made and it had the physical area light and it was set to visible, the artifact was probably from the default low samples. The problem is fixed. Thanks again for your advice.

Anev: Thanks for offering your help, but Ry fixed it.

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