weakness in design.
Issue was: if you delete the 'mother metaball', which is an object with
name without a number, the entire metaball family isn't polygonized. Sofar
so good, where it not that rendering still worked, because it searches all
objects in the scene for a family member with lowest name.
Doing such a search within the main drawing loops will become a major
slowdown, so this better isn't done.
I don't mind sticking to (documented) consistant behaviour. Alternative is
a flag in object to denote it's a Mother Ball, and check for that instead.
This isn't nice to code in current Blender though... we don't have a signaling
system where to insert such tests reliably, making it very hackish.
Jiri; I hope you can agree with the solution! :) Just want to have tracker
cleaned up, refine it to real bugs.
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