Im working on a project and came across a problem with cycles. I have a turntable render of my building which is mostly ok, but at a certain point the lighting inside of the building (mostly lit by indirect lighting) has a sudden flicker. This is persistent regardless of the number of light bounces, number of samples or denoising or not. Also it is always at the same frame. The scene is lit only by HDRI. Any idea what could be causing this as it is driving me nuts.

Thanks guys


Thanks for all the answers, i figured it out meanwhile that it was the camera fog causing those flickers. Cheers everyone

Mosque turntable (Flicker occurs in the first 2 seconds of the vid)

  • $\begingroup$ are you rotating the turntable or the camera? If you frame by frame (Vimeo: hold SHIFT down while using left and right arrow) you can see the shading change in a way that looks like something has started casting a shadow. $\endgroup$ Sep 6 at 23:50
  • $\begingroup$ Hi, thanks for replying, it is the camera rotating and everything is static in the scene. Could it be some render setting in cycles which i missed? $\endgroup$
    – nyultap
    Sep 7 at 1:04
  • $\begingroup$ providing your blend file would help... $\endgroup$
    – John MC
    Sep 7 at 1:51
  • $\begingroup$ I don't think you missed anything. I think that you're see the shadows change as certain light sources are blocked from the camera because of math. You would see similar shadow changes in a building if you walked around outside it looking through the windows. It's unfortunate that the changes last such brief periods that they look like flicker. Could you cheat with a bit more ambient light? $\endgroup$ Sep 7 at 14:12
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    $\begingroup$ I agree with @JohnMC Please upload your blend file to your question (How to add a blend file) $\endgroup$ Sep 7 at 14:54