flickering animation vray 6.1

getting flickering/ ‘fireflies’ in my animation- Screen capture - 22056ec3af8a20d96597b20344d0310b - Gyazo

CAD vehicle, dome light, hdr has a bright sun, car doesn’t move camera is moving slowly panning.

bright spots on vehicle are flickering in specular and reflection channels.

tried settings;
4/50, .005, subpixel mapping on, Light Cache set to Animation and 8k subdivs and 16 retrace. tried path guiding, no change.

tried lowering max ray intensity to .01, no change.
Tried prepass for LC and didn’t see a change.

I don’t know what to try next.

dang, anyone? its really screwing me over on a project at the moment I’m quite stuck on this issue :sad:

Seems like it’s probably the sun in your HDRI that’s the issue? I’d test by removing that first of all. Edit your HDRI.

you know everyone told me that but we shoot our own hdrs so I refused to believe it. we shoot our sun with an ND filter to capture the full range, just like the ones on hdrihaven. but turns out the artist used too small of a mask when adding this ND sun, changed that to a large soft one and boom problem solved.

Thanks for pushing me to take a closer look. :sweat_smile:

Your render looks good btw, but for the hdr issue the sun is too small. So you either want to blur that area a bit, or raise the min subdivs also.