Surface Interference Artifacts


I’m designing a co-molded product that has both transparent and opaque materials. To achieve this in rhino, I have two closed poly-surfaces made with a boolean difference. Where these two bodies touch, I get interference artefacts as these two surfaces are on the same plane. This shows up in both viewport and in my VRay renders.

In reality/production, there wouldn’t be an airgap between these two materials. Does anyone know of a way to remove these artifacts (atleast in VRay) without modifying my model?



I don’t have a good fix for this. The only thing I can think of would be to place one set of the interfering surfaces on a different layer and turn it off. In this case it would be a transparent surfaces that are doubled by the red ones. Not a good option but it would eliminate the double surfaces.

Thanks, I had expected that may be the case.

Hi Paul,

What you could try is to apply a displacement on either (or both) of the objects.

If you choose an all black(or white) texture for displacing and set the black/white point to a small negative value.


that’s called Z-fighting and it happens when you draw two surfaces on an identical plane… (a plane doesn’t have thickness per se and you’re effectively putting two materials on the same exact plane and the computer doesn’t know which one to display…

in reality, even if it’s at a microscopic level, there would be an airgap between the two parts and the surfaces of mating parts wouldn’t ever truly occupy the same exact plane/space.

@Willem’s solution looks pretty sweet… i rarely encounter the need to have a transparent part butting up to another surface in a way which would be so obviously visible but next time i do, i’m going to try it out instead of separating the surfaces… thanks for the idea.

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Thanks for the replies! @Willem That looks like a really elegant solution! Removes any need to mess with surfaces, Thanks.

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