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Beamtracer
05-18-2003, 05:28 AM
I've been getting some bad banding problems when using volumetric lights.

In this example, I was doing one of those logos cut out of a polygon, with a volumetic light shining through the hole, to create beams of light eminating from the logo.

Although the volumetric light was set to 'best quality', banding artifacts were still very noticeable.

Has anyone else had such troubles with volumetric lights causing unwanted banding? Is there any solution?

Mylenium
05-18-2003, 06:15 AM
Well,

This cannot be avoided totally since LW will not allow you to refine sampling distances any further. I normally render all volumetric lights against black and then blur them slightly in compositing. I then overlay everything in "Screen" mode onto the RGB image. This also has the large advantage that you do not really need volumetric antialiasing. Of course this will change the look a bit and cause some minor incorrect edges but will be good enough in most cases.

Mylenium

Beamtracer
05-18-2003, 03:12 PM
Thanks, Mylenium, I'll blur it in compositing.

It's a bit disappointing that close-up volumetric lights can't be used as they are.

Josh655
06-04-2003, 01:01 AM
So you are telling me you cannot get smooth volumetric lighting cones? Damn I should move over to 3d studio max. But seriously since I am a newbie, how do I do this blurring in compositing, in English please.

toby
06-04-2003, 01:56 AM
basically you render the logo and the vol lights separately, import the frames into a compositing program like After Effects, (or Photoshop for a still), layer the vol light image over the logo image and set it's blend mode to "screen".

And believe me, you'll find plenty of things 3DSMax can't do as well as LW, if at all!