[ODE] bbtree parent boxes constraints based on ode joints

[Piotr Obrzut]

Hi,

   i'm making mine own col. det. system which is variation on BBtree
   algorhitm system for mine hierarchical model which consist of some
   parent-children related boxes (this model is based in fact on cal3d
   model, this boxed model is build in such a way which allow me to know after
   collision which mesch, and which bone was affected by this
   collision).
   
   It is based on simple idea: when it check collision between
   2 object (this object may have some hierarchy) when the collision occure
   it will check collision between children of collided objects
   (of course when this object have some descendants). Collision
   checking should continue recursive while both objects will have
   some children. Therefore every parent box should "contain" all
   descendants boxes in every situation - position of box depends indirectly
   on rigidbody position (it change cal3d bone position and this
   position defines box position), so every parent box should be so
   big that it will contain all child boxes in every posible relative
   pos to the parent.

   The question is: How can i make parent box as small as possible
   when it should contain child box in all its posbile positions?
   (positions of both boxes depends on 2 rigid bodies pos. constrainted
   by known joint)


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Greetings,
 Piotr Obrzut