Global illumination leading to image variation I have a 3D scene I use to generate some images which I then process in Matlab. I noticed that when global illumination (GI) is not enabled, rendering always generates exactly the same pixel-for-pixel image (as far as I can tell). However, when I enable GI, the image is not exactly the same. I have been told (I originally accidentally posted here) that GI is stochastic and so this is to be somewhat expected. However, I am curious if there's any way to avoid it (while still using GI).

Thanks
If you can make your samples deterministic (the same from run to run - don't base random sample points on time or any other non deterministic value), it will be a stable rendering that you get every time.