Operating system: W10
Graphics card: 980Ti
Broken: 2.80 19-04-07 00:42
Short description of error
Curves transformations are computed incorrectly while their parents are moved. It can be fixed just by trying to move them as independent (but still not removing the parent), and then cancel. They will recompute everything correctly and look OK.
Problem was present in 2.79 and I've been thinking it will be fixed in 2.8, but it's even worse now.
Due to changes in groups -> collections, a lot of stuff is being done in a wrong way if the source collection is invisible or in other locaiton than linked one.
Now look at this, in viewport I have 'fixed' the filament curve by simply moving the lightbulb while it's original collection was visible, then turned it off and I could move this lightbulb with source invisible - lightbulb was being updated correctly.
But after hitting render - picel.
Now it seems to be really connected to the viewport and render visibility. If something is invisible in viewport but visible in render and vice versa it can affect strange stuff.
Exact steps for others to reproduce the error
Set curve to have a parent, move parent - curve is placed incorrectly now. Try to move curve (you can cancel) - curve is now in right place.
In the attached .blend, when you open it - select rendered view, you'll see that filament is outside of the bulb, turn on view on "lightbulbs" (picrel):
Then expand "lighbulb on joined", select "Szklo.001" and try to move it (default G), you can move - or try to move and cancel.
Filament will jump back in the bulb in both source and instanced bulb. Picrel.
You can now turn off "Lightbulbs" colleciton view and move instanced bulb around - it will be continously correctly updated.
Yeah. Render it. Surprise.