Some troubles with sleeping and size of collision primitives

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are you using newton 1.53?

i use 2.30

[Julio Jerez]

In 2.00 bodies are always awake, meaning they always get a force and torque call back.

you is is only when the sum of the net force and net torque add to zero the a body is considered sleeping.
you should not have any problem.

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now i can't say to a body something like NewtonBodyAwake to awake body and bodies which is in contact with it, now i use the hack - i add small force to a body to awake it. problem is appeared when i try to do the same thing with static body(mass=0). in this case, body becomes awaken (NewtonBodyGetSleepState returns false), but body still not interacting with dynamic bodies. i think that body with mass=0 is designed to be static and logic says that this kind of body can not interact with other body if it in sleeping state, but it possible when we call NewtonBodySetMatrix. Static body can loose contacts, can reach contacts when it "teleported" by setting it matrix, but it doesn't work like i say. In other words the problem is what static body can not awake dynamic body.

[Julio Jerez]

yes body with mass equal zero are always static.
if two bodies with mass = 0 come in contact they do not collide. Is that what you are trying to do?

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yes body with mass equal zero are always static.if two bodies with mass = 0 come in contact they do not collide. Is that what you are trying to do?

no. one of my body is static, another is dynamic. when i move static body by NewtonBodySetMatrix it does not come in contact with dynamic body if dymamic body is in sleeping state.

[Julio Jerez]

if you move a static body, it will penatrate any dynamics body that is resting on it,
howver if you set the velocity of the static body to thr displacement divided the time step, before to call teh newton callback,
then the dynamics body will wakeup and move too.

you do something like this.

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staticBody->SetVelocity(staticBodyVelocity))
NetwnUpdate (timestep)
staticBodySetMatrix (matrxi.posit + staticBodyVelocity*timestep);
staticBody->SetVelocity(zeroVector)

Make sure the body on top of the static body as set to autosleep off
it should work. few peopel have done that in thier games.

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now i do something like you say, and it will work fine if i switch autosleep to off.
i knew it works, but autosleep is needed, because of perfomance.
i've found some examples in dCustomJoints. is CustomKinematicController what i seek?

[Julio Jerez]

you need to write code that get the bodies on top of the plaform and switch the autosleep mode when you move the platform, then witch autosleep back on when the platform is not moving
you can find the boded that are touchind the platform very easeely by using the functions
NetwonVodyGetFirstContact(), and NetwonBodyGetNextcontactJoint

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when body is in platform, it works fine because body is moving and not going to sleep. but if i want to create some other interactions (for ex. car hits a stack of boxes) i will get some problems (perfomance + manually setting sleep flag to bodies that potentially can be collided by static body)