Foster parenting (Python script)

This is a way to create temporary parenting, for situations like picking
up and putting down an object, or throwing an object.

Before using, set up the animation completely, with the Child object
holding still at the place where it needs to be at "pickup".  You will
probably need to fiddle with the location and startframe, so be sure to
save a PZ3 before applying the script!

The parent may be part of a Figure; the child must be a single
freestanding Prop.  The two must NOT be parented in the ordinary way!

1. Activate FOSTER.PY.

2. Fill in the parent object's exact external name (like Left Hand) in
   the first blank.

3. Fill in the child object's exact external name (like Ball) in the
   second blank.

4. Fill in the frames where you want attachment and detachment to occur.
   (This is especially fussy and will probably require some fiddling.)

5. If you want the parenting to be like Poser's usual style during the
   time of attachment, hit the "Standard" button.

6. If you want to have the child follow the translations of the parent
   but remain in its original rotational position, hit "Parallel".

7. "Trajectory" gives standard parenting up to the point of detachment,
   and then forces the child object to continue the same motion given to
   it in the last few frames of attachment, all the way to the end of
   the total Number of Frames.  Note that this does not include gravity.
   If you want gravitational fall, adjust the Ytran of the child object
   during these frames.

Copyright (c) 2003, David G. Drumright (ockham)
