Open Simulator with Physics Engine

[Jeremy Fitzhardinge]

Edward Cherlin wrote:
> Has anybody looked at this for the XO?
>
> http://opensimulator.org/wiki/PhysicsEngines
>
> The physics is not very realistic yet. Presumably we could manage
> simple statics and dynamics, with graphs of position, velocity, and
> acceleration.
>
> I would like to have a simulation engine available for integration
> into e-textbooks. What other candidates are there?
>
>   

I've been looking at using Chipmunk (a 2D physics library: 
http://wiki.slembcke.net/main/published/Chipmunk) to do a simple 
activity which allows the user to draw shapes freehand, and then have 
them physically simulated.  By choosing different pens, you can draw 
either fixed, rigid or flexible shapes.  People have already developed 
similar programs using chipmunk, and the demo videos are very 
interesting.  Unfortunately they seem to be under closed licenses.  
Besides, a Sugar version would be most interesting with some kind of 
mesh multiuser component, which would probably significantly change how 
the program evolves.

I've done some very early prototypes on the XO, mostly by running the 
Chipmunk test program.  It was surprisingly slow; I looked at optimising 
chipmunk to use 3dnow, but I suspect the bottleneck is in actually 
rendering (I have not profiled it properly).  I was hoping to use Cairo 
for rendering, but it seems to be a bit too slow for smooth animated 
rendering.

I was hoping to put together and announce something simple for people to 
poke at in the next week or two.

    J