Hello specialists,

I control Acknex-Engine with Stromausfalls's C#-Wrapper. I had a wonderfull working A7-project, until I upgraded to A8. As the release-note says, the physics has to be adapted for A8.

Now my big, after a number of hours of searching unsolved, problem occurs, with my wheel-constraints.

I register a car-entity for physics. Then I want to add a wheel-constraint. According to manual, in A8 the wheel-entity need not be registered for physics.

During adding the constraint, the application throws an AccessViolationException when native function NativeEngFun.pXcon_setparams1(entityPtr, vecParam1Pointer, vecParam2Pointer, vecParam3Pointer) is called.

Confusing is, when I register the wheel-entity for physics, I get NO exception. But when I do this, the constraint doesn't work at all and does uncomprehensible movements. It seams, you MUST not (and not only NEED not, as the manual says) register the wheel-entity for physics when you want to use it for wheel-constraint.

Due to the restriction, that I can't look into the native-dll, it's hard to fix the problem.
This case I tried on my old PC (WinXP, 32bit), too. I also get the same exception. OS could aparently not be the cause.

Does anybody knows this problem?
What can I do to fix?
Is it a recommendation or a rule, to NOT register the wheel-entity for physics?

As the manual says, you must not register the wheel for physics. When you do, you'll end up with two wheels, one real wheel and one physics entity at the same position. That's why you got the strange movements.

I don't know the reason of the C# wrapper exception, though. Check if the parameters of the wrapper function match the parameters of the real PhysX functions. Probably Stromausfall can help here.