View Full Version : Strange render Artifact

12-27-2011, 05:22 PM
Hi @ All!

I've been trying to solve this for two hours or so, but I just can't find what's causing the anomalies. If you have a look at the attached picture you can see that under the arches some of the geometry is rendered very bright which is obviously wrong. You can also see in the top left of the image, where the geometry of the arches is quite close-up that there are some strange "stripe-patterns" rendered into the image. I have pasted a screenshot of the geometry in the image as well, so you can see that it is perfectly round. I have merged all points and I have checked the geometry for mistakes, but I can't find one.

I have removed the material and reverted to a color with smoothing turned on and off, but it still looks like that. When I paste just the arch in a new model and put that into a new scene it renders perfectly.

The scene is lit with a single light-source and GI, but the anomalies are also visible, with no GI.

If anyone could point me in the right direction that would be much appreciated.



12-27-2011, 10:13 PM
I would say the problem is a symptom with a couple causes. First, I'd try adjusting rays per evaluation and secondary rays. Second, adjust your number of anti-aliasing passes. With depth of field and the light issue, this may be causing the banding. The bright areas are likely cause by the accumulation of bounced light along the curved surface.

12-27-2011, 10:32 PM
It looks like some 2 point polys, check stats in Modeler. If so delete them.

Some nice work you have done so far.

I've just started doing Cloitre de Saint-Trophime in Arles. I found a floor plan, now I just have to do the 3d from my photos!

12-28-2011, 04:19 PM
Thank you very much for your kind words and for the solution: of course it was 2-poin polys!

Good Luck with the cloister in Arles. Googled it, looks fantastic.