[ODE] Switching between an immovable and movable body ? and Manual body control ?

[Rob Ruck]

New to the mailing list, and not surprisingly a few questions:

- I know that a static body can be created, i.e. for dgeomsetbody() you pass it 
0/null body id. Which works fine, but why can this status not be changed 
during a simulation; if I create a body, set it to geometry, and then decide to 
make it static, using dgeomsetbody() with body id of 0 (and maybe disabling 
the body, just so the geom and body match up). However, if a geom has 
previously had a body set to it, setting the body to 0 doesn't work the same 
as if no body had been set, the geom no longer seems to be collidable, why 
is this ? Will there never be a simple flag setting akin to Havok's pinning, 
whereby a bodys geom's are all set to a mass of zero, making them 
collidable, but they never move ?

- In general I know its a bad idea to assume control of physics objects, 
causes interpenetrations, etc. But if I need to put an object under say mouse 
control, is it best to use a constraint whereby by said object is one part of the 
constraint and the other is simply a co-ordinate transformed from screen to 3d 
space ?

Thanks for any answers


--Rob Ruck
--ICQ#66577271
--mailto:bobruck at btinternet.com