I'm rendering an animation above some clouds, mostly all of the 450 frames of the animation render fine, but I have 2-3 frames which seem to be corrupted, even when I try to render them as stills, they have a weird grainy noise through them.
Any ideas why this is? -image attached.
Possibly undersampled extreme motion blur? Does the camera view change dramatically on these frames? Does it render the same if you disable motion blur?
Great, thanks. Disabling motion blur fixed it.
Must be something going on between those frames with the imported camera affecting the motion blur.
Yes, very likely there is an extreme rotation where e.g. the camera flips over, goes past 360 degrees of rotation, etc. and this is causing a high degree of motion blur that is difficult to sample and thus noisy. Ideally the camera problem would be resolved, which would address the core issue.