If i make them proxies everything works OK but when I try the same method on a more complex object (111.000 faces) it takes ages to render a single frame.
…but I think I found the cause of all evil.
If setting the scale to anything else than 0 but quite close to it like 0.001 everything works OK.
It’s a strange behavior but I’m not sure if this is considered a bug.
If anyone has an explanation I would like to hear it.
I’ll wait a couple of days if theres no answers or proposals I’ll mark it SOLVED and not a BUG (though I still have my doubts).
I think this is a bug. I never scale objects to zero and it’s evidently not a good thing to do, but this should not crash blender and it should not cause other objects not to render.
I don’t know whether to report or not, because it has been reported in the past:
Object and Group transformations assume matrices can be inverted, a zero size won’t work for that, that’s a known limitation in all of blender. The only thing we can do is prevent such values and replace with 0.0001 in code or so, so things at least work predictably.
I’ll put that on todo for later.
BTW:
“Typically a scale of 0 should not render anything.”
That is not true, the object has been transformed somewhere to infinity… this is not desired behaviour.