Re[2]: [ODE] dCylinder with new collision detection system

[slipch]

Hello Olivier,

Wednesday, January 22, 2003, 4:42:31 PM, you wrote:

.....................................
>> Currently I use a trick which allows to set contact points near the
>> place it should be.
>>
OM> Ok, I am just facing this problem. Two cylinders are interpenetrating 
OM> each other, collision is detected too late...

This can happen due to above mentioned problem only in the case of
cylinder edge - cylinder edge collision i.e. when rings on cylinders
edges touches.
Any geometries can interpenetrate also due to CFM, ERP settings.

OM> It's a bit annoying. Do you have some schedule to fix this issue ? If 
OM> not, could you give me more details about this mean points technique you 
OM> are thinking about ? I am not sure I could help doing this, but I may try...

It is a simple idea for problem case. I this case the ring on one
cylinder edge cross both lateral surface of the other cylinder and its
flat circle edge each in one point (and vice versa). The idea - find
both points and mean point between them that lying on the ring MP1.
Doing the same thing for other cylinder we have two points MP1, MP2.
Vector MP2-MP1 may be used as contact normal its magnitude as
penetration depth and point (MP1+MP2)/2 as contact position.
Case of cylinders separation must also be carefully regarded.



-- 
Best regards,
Konstantin Slipchenko                            mailto:slipch@gsc-game.kiev.ua