PDA

View Full Version : blocky shadows using final gather

what?
08-18-2005, 05:04 PM
Hi, i'm trying to render a simple object, which is a display box, with smaller boxes in it. the boxes are placed one infront of the other, in 5 rows. i'm rendering in maya using final gathering. the box is then rotating 360 degrees. everything is fine except for at the end of the animation the shadows which are cast by the boxes in front turn very noisey. like each frame the shadow is noticably different to the last, and looks bad.

i've tried tweaking every setting under the sun, but just can't sort it out.

any advice?

cheers
Ian Jones
08-19-2005, 10:59 AM
Shadow maps or raytraced shadows?
what?
08-19-2005, 02:00 PM
sorry forgot to say that! doh! well, i'm just using a half sphere with a white texture applied to it. this is the only light in the scene. so no lights, with no shadows turned on. but obviously raytracing is on for final gather to work. it must be one of the settings in final gather. i've increased the final gather rays to 4000 and it does help, but even at 4000 it doesn't get rid of it totally, and takes an eternity to render.
Ian Jones
08-20-2005, 02:22 AM
So your using a self illuminated white material on a sphere which is acting like a geometry light?

I don't think you will be able to fix this with your current lighting method. There are limits to how well you can use a geometry light with mental ray because you can't control the attenuation, and intensity very easily and this 'overbright material' which is outputting the light is what is causing the blotchiness in the shadows. Can you perhaps use a proper area light instead?
what?
08-20-2005, 01:59 PM
that's what i did in the end. just didn't realize this wouldn't work that well. cheers for the help.
CGTalk Moderation
08-20-2005, 01:59 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.