[ODE] ode & dynamic skeletal animationsystem

[Dietmar Suoch]

Anselm Hook wrote:
> This is a common problem.
> 
> Often in the entertainment industry we will have motion captured movement
> of a puppet in space.  Or alternatively an artist will animate a series of
> "statues" to create the appearance of movement.  However we want our
> animated characters to be 'live' and to interact with their environment.
> 
> Your approach of mixing may work actually - but it may not handle
> collision cases very well.  Ultimately you are "coercing" or "popping" the
> dynamical system and its internal state may not gracefully accept this.

collision is concern right now.
it's a prototyp, so i do not worry about this yet.

but it should be a concern in the future of course.
i'm new to physcis and i do not understand the problems you mean.
couldn't i check the final position if it is valid (not colliding)
before drawing it?

> Trying a purely dynamic puppet may also be worthwhile.

hm, i don't think that a purely dynamic puppet would look
good all the time. but it might be ok for explosion-,
falling- and death-animations.
(like unreal tournament 2003 switching to
karma ragdoll physics after playerdeath)

> The animation data contains enough information to derive the kinds of
> forces that would have to have been applied to the individual bones.

> If you extract these forces then you can re-apply them to a purely
> dynamics based rag-doll and you should be able to visualize the same
> apparent animation except that it will be dynamically driven.

how? can't quite follow you.
you mean by calculating the force from the velocity(acceleration)
of the bones and the mass of the bone?

do you think that would be possible?
sounds to me like really intense calculations every frame.

> Once it is dynamically driven then it can also be influenced by other
> dynamics based forces.
> 
> In practice the approach is more likely to involve applying forces to
> bones every iteration in order to attempt to get them to their registered
> position.
> 
> You need to decide the maximum strength and application position of the
> kinds of forces you are going to consider legal in attempting to coerce a
> dynamically drifting bone back to its correct position.
> 
> I have not actually done this myself so your mileage may vary; but I have
> seen others do it and it did seem to work for them.

which other? got any links?

> In any case, good luck, it sounds like a worthwhile problem to solve.
> 
>  - a

thank you for your input
dietmar