[Bf-funboard] contraints - a problem.

Jonathan Bartlett bf-funboard@blender.org
Wed, 9 Jul 2003 06:47:53 -0700 (PDT)

> the replacement of current parenting with "ADD
> Loc/Rot/Size" constraints. unfortunately, i don't have
> FTP access at the moment and can't post diagrams, so
> you'll have bear with me while i try to explain.

I don't think this is actually an issue.  What you have, instead of
inheriting Loc/Rot/Size, you have "constrain to coordinate system", which
would have the effect of any movements of OBJ_B be within the coordinate
system defined as the location/rotation of OBJ_A.  So, it's not inheriting
OBJ_A's properties, it's inheriting the coordinate system defined by

There may be small gotchas in relation to this, such as what happens when
the centerpoint of OBJ_A changes.


> using current parenting system:
> OBJ_A at xyz 0,0,0 is the parent of OBJ_B at xyz
> -2,0,0
> OBJ_A is rotated 90` around Z, placing OBJ_B at 0,2,0.
> so, both objects are rotated 90`, and OBJ_B has moved
> two units +X and +Y. OBJ_A has not moved. all objects
> are, in effect, components of one grand object.
> using proposed "ADD Loc/Rot/Size" constraints:
> exactly the same situation, however, as OBJ_A has not
> moved, OBJ_B has no location to add, therefore doesn't
> move either. Without the linked relationship of
> parenting, the constraints would not perform the same
> job. an add rotation constraint would have a similar
> effect to the "Rotation/Scaling around individual
> object centers" button, except as a constraint, not an
> interaction option.
> In light of this, I would like to propose a complete
> "parent" constraint. This would be in addition to the
> individual "ADD" constraints (which i think are an
> excellent idea)
> later
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