Double check that you are use either the Good or Best settings in the light cone filter menu.

Mark, I did change to best when I changed from Shadow buffer to Raytraced, but it still looks about the same. MAybe it's the scene setup?

How exciting. ;) I have had this issue on occasion but I don't think I've ever solved it the same way twice. Sometimes adding a backdrop (even just putting in black as a color) has fixed it. Other times I've changed the render resolution from the default 72 to 144 or higher. Most of my stuff is rendered at 300ppi and I never see the problem - I thinks it's just at the lower resolutions that it happens more frequently. For whatever my instincts are worth, I'd try the backdrop thing first. The "rings" aren't occuring in places where the light has interacted with something.

Hi

I think u should unckeck the "interpolation" param...this is probably what create these artefacts. Also u probably don't need the "improved edge", what will slow down your rendering ... Hope this help :-) Pete

Message edited on: 09/22/2004 15:48

I do not think it has to do with render settings. Actually, I think it might have to do with 'traditional' banding, the fact that you are generating stept between tints (shades of color) that are so small, that sometimes there has to be a slight jump between one and the next.
In greyscale there are only 256 shades, but I do not know how many steps can be made in an RGB channel in Cararra.

If this assumption is correct, adding a little 'Turbulence' to the light cone should help, a non-egal backgrond or, the trick I use when this happens for material for print, adding a bit of noise in post.

But I might be totally wrong on this...

I agree with the "traditional banding" idea. I've noticed it occasionally. The shades available should be a function of color depth so make sure your screen colors are set as high as possible. Still and all the problem is probably in C's render engine. Maybe just a rounding problem in some algorithm. I would just try adjusting lighting intensity or ambient intensity up or down.

Message edited on: 09/23/2004 06:32

Really I'd improve the shadow accuracy from 4 to at least 2. Thats likely one thing thats causing it. And deselect interpolate. Make sure also that you are using raytraced soft shadows. Brian brian@vizualds.com http://www.vizualds.com