[ODE] Re: Dinamic gravity vector

[Gary R. Van Sickle]

> > I am developing planetary surface and I want to use ODE library for 
> > phisics. Thanx for developers!
> > But is it possible to make not global vector gravity but 
> just "gravity 
> > point" or mass centre of planet?
> 
> try using explicit Forces from each planet to each other 
> planet (planet
> pairs) and set global gravity vector to 0
> 

This unfortunately won't work well.  This will effectively be Euler
integration of the gravity vectors, which will result in the planets
spiralling ever outward from the sun, regardless of the magnitude of the
gravitic forces involved.  I don't believe there's any way to do this stably
with ODE.

There must be some way to do this in general, but I don't know what it is.
Probably involves conjugates or gradients or some damn thing ;-).

-- 
Gary R. Van Sickle