'matrix_world.translation' setter is broken when parented to Curve #71278
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Reference: blender/blender-addons#71278
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System Information
Operating system: Mac OS
Graphics card:
Blender Version
Broken: 2.80
Short description of error
Setting the translation of an object via the Python API, when parented to a curve, does not behave as expected. See the attached screenshot below:
Instead of setting the translation as expected, it seems that the translation setter is adding to the value. I believe this behavior is caused by the setter reading the curve's origin, assuming that this drives the child's location, while the child's location is actually being driven by some point along the curve.
Exact steps for others to reproduce the error
C.object.matrix_world.translation.x
C.object.matrix_world.translation.x = -1
C.object.matrix_world.translation.x
Added subscriber: @bblanimation
Added subscriber: @JacquesLucke
Changed status from 'Needs Triage' to: 'Confirmed'
I can reproduce the issue. I'd actually be surprised if that would have worked^^
While this is an issue, I don't think that Blender can make this work reliably in all cases.
Added subscriber: @mont29
Changed status from 'Confirmed' to: 'Archived'
This is indeed not expected to work, in fact it won’t work for any 'advanced' parenting (to curve, to bone, etc.). Thanks for the report, but no bug here, just (reasonable) limitations of existing code.