Balls, render artefacts?!


i’m having issues with a render, i’m using the physical renderer in R25 with gi & ao. But every so often these artefact’s pop up. Has anyone else had this issue?


Do these balls appear when you have AO turned off?

I seem to remember having this issue with incorrect AO sampling distances, not the big balls but the smaller spot artefacts.


Can you upload your file ?
Did you try the old cut and paste into a new scene ?


as i was using a procedurally generated texture, i thought id turn if off & try a render…


so the AO was left on for this render, so i think it was the procedural texture was making the small dots, but the big spots remain?!


It’s impossible to help you get to the bottom of this if you don’t post information like your render settings, whether you’ve rerendered without AO or if the artefacts happen on the same frame or are completely random.

With decent GI and lighting you shouldn’t need AO for a simple setup like you’ve shown so I would ditch it and rerender and see if those artefacts reappear.

These large black ball artefacts could be stray shadow samples hitting the flag from way off in the scene. Have you got something with self shadowing turned on like a sphere with an HDRI on it? Try limiting bounces.

I’m just guessing without seeing your settings and how you’ve got your scene arranged.