View Full Version : Color Bleed

04 April 2004, 07:57 AM
Hi! Can somebody help me, how do you supervise / adjust Color Bleed? Thanks. I use Msx6/MR3.2

04 April 2004, 05:12 PM
Use a photon base map in the photon slot of the materials to control the bleeding.

Basic material with GI & FG:

Material with photon map applied and adjusted to not allow color bleeding:

And finally a sample scene to see my settings:
Download Color Bleed Scene ( )

Trace depth can be used to control the bleed as well, but it affects the entire scene. The photon maps can be used on single materials for more precise control.

04 April 2004, 02:24 PM
Let's complicate a problem. There is a room. A ceiling and walls we paint in white (255,255,255), and a floor in brightly red (maximum). Try to get rid from Color Bleen with use GI and FG. From Omni blida it is less than from Spot/Direct. In the schemes of illumination I use Free Area (sizes = to sizes of a window) and mr Area Spot.
folical9 Help me please to decide this task. Sanks

04 April 2004, 07:48 AM
Well, I tried and I can't totally stop the color bleed when the floor is 100% red. The photon map helped a little, but wasn't able to remove all of the color bleeding.

I suppose the only way to remove color bleeing in an extreme case like this is to render in separate passes (if possible). Render the room with a white or grey colored floor then render with the red floor and mix the two in photoshop. :shrug:

04 April 2004, 04:41 PM
couldn't you also use an advanced overide material on the floor and then adjust the color bleed there????


04 April 2004, 12:05 PM
Thenks. It d`t work

06 June 2004, 11:40 PM

color bleed in mental ray was an issue i had for days now. thanks a lot jeff!!!

i just wished this were documented in the help files...


08 August 2004, 04:59 PM
it's because of the spotlight, the more consentrated the light the greater color bleed you get, if you only use omni lights you probably wont get any color bleed at all.
If you must use spotlights, increase the decay value, increasing decay gives less color bleed, decreasing it will give more color bleed.
If you have omni lights and want color bleed you just decrease the decay.
default decay is 2, and decreasing it to 1,6 with omni will usually give a fair amount of color bleed, so dont increase or decrease by to much.
Hope this helps :)

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