[ODE] Mass and trimesh collisions

Patrick McColgan patrick at torcinteractive.com
Mon Jan 24 17:38:18 MST 2005


I've been working with ODE to implement a character controller, it has 
progressed well however I had been using a cyclinder with a total mass 
of 5 units and when I changed the total mass to a more realistic 80 I 
found that the avatar (moving at around 2.5 units per second) started to 
move through walls and when falling would fall through floors.

The collisions do register, they do apply a force in the right direction 
which slows the avatar but as I have been stepping through the program 
it appears that it just isn't scaling the force enough despite 
apparently using the mass and inverse mass in calculations.  Using the 
joint feedback function I get a force of about 528 units twice and I 
think I need a force of around 12, 000.

Has anyone else experienced this, or is this a known issue?  I had a 
look in the archive but there is very little on it, more seems to be on 
mass ratios problem between two bodies.  Is there a limiting parameter 
with regards to mass in collisions?

Setting the ERP to one helped on walls but not floors and the program is 
stepped at about 1/60 hz although I did try it at 1/100 but it made no 


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