[Bf-committers] new IK algorithms in Blender

Herman Bruyninckx Herman.Bruyninckx at mech.kuleuven.be
Tue Jan 13 17:15:00 CET 2009

On Tue, 13 Jan 2009, Brecht Van Lommel wrote:

> From the animation point of view you quickly get questions like:
> * How to interactively edit animation at keyframe 200 without having
> to wait and rebake from frame 1 each time? Is this possible at all?

It is: the constraints determine the _instantaneous_ motion, so the baking
has all the state information that is necessary to continue from a given
point with modified constraint or armature parameters.

In addition to the instantaneous IK solver, robot programmers (and I am
quite sure also animators) need:
(i) "logic scheduling" of such instantaneous motions supported by some form
of a finite state machine (for which the Game Engine already has a decent
code base!); and
(ii) pre-programmed (but customizable) "gaits" and "postures", that is,
sets of "IPO curves" that give nominal motions such as walking, reaching,
running, picking up things, etc. (In your words, such gaits are "baked
IPOs" that can be resimulated with customized settings.)

So, the questions you raise are to the point, but the (possible) solutions
to them are within our medium term vision of the development.


> * How to keep animated data and simulated data separated? By layering
> one on top of the other? Like layering actions in the NLA perhaps?
> * How to tweak simulated results? How do you make it clear to the user
> that edits to simulated data will be lost? Or can such edits be
> layered too?
> However from the robotics point of view maybe all you want to do is
> specify parameters, and then run the simulation from scratch each time
> and inspect it? In that case the solution can be simpler but perhaps
> not as suited for animation.
> Brecht.
> _______________________________________________
> Bf-committers mailing list
> Bf-committers at blender.org
> http://lists.blender.org/mailman/listinfo/bf-committers

   K.U.Leuven, Mechanical Eng., Mechatronics & Robotics Research Group
     <http://people.mech.kuleuven.be/~bruyninc> Tel: +32 16 322480
   Coordinator of EURON (European Robotics Research Network)
   Open Realtime Control Services <http://www.orocos.org>

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

More information about the Bf-committers mailing list