[ODE] The pushing of a morphing model

[Jon Watte (ODE)]

Zanshin wrote:
> There are some situations I don't know how to model.
>
> a- A sphere slowly transforms into a cube; as the cube corners form, 
> they push other objects.
>
> b- A cube has another cube over it. The cube under transforms into an 
> inscribed sphere and the upper one falls.
>
> c- (hardest) There's an ethereal cube that occupies no space. It 
> gradually turns "real", pushing other objects away from it's center.

Note that ODE has two components: Interference detection (collision), 
and Constraint modeling. If you can figure out what needs to be pushed 
where, the constraint modeling can do the job. The ethereal cube that 
solidifies is simple; you start out with a very high CFM and very low 
ERP for those particular contact joints, and lower CFM/increase ERP as 
it gets more solid (you'll need to tweak the curves you use here).

For A and B, ODE has no specific functionality to accelerate collision 
testing between morphed meshes, although you can perform a "re-fit" on a 
calculated collision mesh faster than you can re-calculate that mesh 
from scratch.

Cheers,

                      / h+