[ODE] Collisions for a long time

Simon Adler s.adler at sensator.com
Tue Dec 13 00:40:45 MST 2005


Hello everybody,

I need some suggestions about a Collision Problem. I've Problems to
stabalize my System and I am not sure if it's possible.

I have a non plane Ground represented with a Trimesh and I've got some
Characters
represented with an BoxGeom. I use forces to move the Body over the ground.
To accelerate I use a RelForce, so the Box is moving forward. ODE schould do
the orientation Stuff etc.

I've some strange behavior. The Trimesh is a Geom without a body, so It
schouldn't possible to break through. If I walk, sometimes my Character
breaks through and the ERP throughs him back.

Some Values for your Consideration:
world->SetERP(0.5f);
world->SetGravity(0,-9.81f,0);
Character Mass (15.0f)
Accelerate Force (0,100,0);

A little comment to the accelerate Force. Every Timestep I check if the body
has reached a maximum speed. If it is, so I don't apply the Force again.
With this, I can
climp higher ramps.

My Problems are the Instability and the drift at all.

Ich have some thoughts. Is it possible to use a Trimesh as ground? Is it
possible to handle long time Contacts with a Trimesh ore with Geoms at all,
or are there Still Problems in ODE.

I tried Autodisable Flags too, but my Problems grow. My Chracter seems to
sink through the Ground. Because this goes very slowly there is no ERP Force
applied.
After the Body has reached a speed greater than the AutoDisablesThreshold,
the
ERP Force is applied and my Body is thrown through the Air!

Need some suggestions!
Thanks a lot

Simon




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