Rendered this in cycles, everything is smooth except for the couple of white pixels.

4000 passes, all the grain is gone but you can clearly see the bad pixels. What can I do to prevent this from happening?

Moved from “General Forums > Blender and CG Discussions” to “Support > Lighting and Rendering”

fireflies are very common with glossy shaders. you’ll have to remove it with gimp or photoshop

I’ve used luxrender and blender internal and this doesn’t ever happen. Cycles is still very young though hopefully that will get fixed.

There are different “bad pixels”, one cannot be avoided, it is feature of Monte Carlo solver. Other result of bugs in shaders, and must be fixed. Latter can be seen as very bright and not changing even after very many samples. I think that Glossy and Glass shaders can produce them in rare cases. But in your case pixels are colored, it confuse me. Looks like bug, but not in shader, maybe some very rare numerical over/underflow.

I use cycles commercially and I battle with them damn fireflies everytime i make a render! Aye glossy material make`em but also if you use mesh emission lights and dont unclick the “camera” option in its ‘Mesh’ properties, it can make those fireflies appear.
Also make sure that the glossy’s material Roughness is anything BUT 0, when pure zero is there it produces white dots like a mad man
painting white pixels on your screen after his 50th beer :smiley: