[ODE] Box stacking problems

Joe Ante joeante at liquiddestiny.com
Thu Feb 20 12:39:23 2003


Hi,

I have setup a test scene containing 4 stacks with 4 cubes each.
Then I pushed the outmost cubestack towards the others, so that all the
stacks touch each other. When all the 4 stacks are somehow connected through
contacts to each other, ODE becomes very slow(2fps on g4/667), starts
sending messages in the lcp solver dSolveLCP  (LCP internal error, s <=0))
and after some time crashes when trying to allocate memory in dSolveLCP:
line 1125, dReal *L = (dReal*) ALLOCA (n*nskip*sizeof(dReal));


I also  tried adjusting the erp and cfm parameter.
I am using a gravity force of 9.81. (When I use a gravity of 1 the slowdown
becomes less and the crash seems not to appear)

I am using 4 contact points for every collision and fixed timestepping (50
frames/sec)
I am using ode 0.035.

Is this something other people experienced as well?
Is simulating a scene like the above just too hard to solve for a physics
engine?
Will it improve with further releases of ode?


If you had no problems with scenes like this, can you think of anything that
I am doing wrong?
Why does ode crash?
Why does it get so slow.
What does the LCP internal error mean?

Joe Ante