Strangely rendered results

I am stuck with this problem: my model (at frame 1, when the visible blue arrows should be fully opaque) renders as attached: they seem to be partially transparent, at random locations, in a noisy way. Can anyone explain this and point out what I am doing wrong? I am happy to hear any other comments too (how the model could have been set up in an easier way).
I must add that at two random times during this evening the 3D rendered view in the viewport looked OK, without this strange behaviour. I could not associate these with any particular action.
Thank you
Best regards


Tesla cavity v03.blend (1.15 MB)

Some objects have negative scale, which is why in the render every other arrow looks different. Because of the negative scale, their surfaces point to the other direction. Ctrl+A -> scale to apply, edit mode, select all, ctrl+N to recalculate normals.

There are overlapping objects in the render because you’re only hiding them from the viewport, not from the render.

Mixing values should be inside the range of 0-1, not -1-1. Not all materials have that.


Tesla cavity v04.blend (624 KB)

Looks like JA12 fixed it. Here’s what it looks like now.

Background added for flavor

Thanks really a lot for your help, and sorry for responding so late, I was quite busy. It solved the problem. The two points were:

  • negative scale --> messed up normals
  • visibility switched on/off only in the viewport, not in the render

mixing values <0 are nonsense, but the software allowed it and it was an easy way to create the desired shape in the positive region (when the value was negative, the object was meant to not be rendered anyway).

Thanks again.