Displacement noise and polygon screw-up

[ThomasVandenAbeele]

Hi all!

Since this has happened regularly I've decided to post and ask for help! When I use displacements I often get ugly noise or other artefacts, like in the image below, around the dimples. The displacement map is perfect white around the dimples, mid level is at 1.0. Besides this noise that you still see, I also had MEGA-noise from what seemed like noisily intersecting geometry, from the plastic bottle through the printed sleeve material - which was at .1mm distance from the plastic. Without displacement it was okay, when adding displacement to the bottle it screwed up, even though under the sleeve displacement was white, and with mid level at 1.0 it should not have moved. Right?

Any ideas or remedies?

[ThomasVandenAbeele]

For your info, here is the render when the sleeve is only at .1mm distance from the displaced plastic bottle. In theory, displacement should be zero where the sleeve, for the plastic bottle, because the disp map is white there, and mid level is at 1.0.

[ristoraven]

Play with ray epsilon setting.. ?

[ThomasVandenAbeele]

I tried that, but it's at 100um now, and if I set it to 95um the bottom part goes dark. Hold on, I'll do a render to show you.

[ristoraven]

Try setting it on 1 mm..

[ThomasVandenAbeele]

Hi Ristoraven,

Thanks! That did the trick! I naively thought that if errors showed up setting it lower was the way to go, but higher worked well!

[ristoraven]

Great,

As a rule of thumb I have made a saying that applies to everything also in real life, that if everything looks misplaced or f'''ed up, I need to check my ray epsilon values.