[ODE] small sized capsule on heightmap problem

Martijn Buijs buijs512 at planet.nl
Thu Sep 28 04:58:51 MST 2006

rod wrote:
>    I don't think it is a tunnelling problem. The thin capsule bobs up and down 
> just on/below the terrain surface, and doesn't continue falling through. So 
> it looks like collision detection/response is happening, but the contact 
> forces are wrong somehow ?
>    Could anyone else test this ? Any capsule of radius 0.03 and a length of 
> 0.5, should show the problem, on a heightmap terrain of 512.0x512.0.

I did a variety of tests with very small objects before I submitted the code (things may have 
changed since) and never encountered similar problems. Those objects where similar in size as your 

I suggest you check for negative geom dimensions (not sure if those are valid or handled well by 
ODE). Also, if the mass is to great the object would continuously penetrate, sink into the ground 
and "float" up again.

Have you tried replacing the terrain with a plane? dHeightfield uses planes for collisions 
internally, if it is a collision issue/bug it may occur with planes as well.


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