sleep problem's and margin

[lo-th]

Hi i can't set sleep at start ? work with gravity 0
body.sleep() don't work i guess ?

also what about margin ? are the shape have margin ?

[jcyuan]

show some of your code please.
body.sleep should work i think.

no, there is no margin on a body, it's unnecessary since you can create your body a bit larger then your display game object so that it looks like there is margin.

[lo-th]

Hi mm no body.sleep don't work
code is like
https://lo-th.github.io/phy/#basic

at start object should sleep
i put a timeout to wakeup

but i see original rapier have same problem's cause by gravity

[jcyuan]

        const bdDesc = RigidBodyDesc.dynamic();
        bdDesc.setCanSleep(true);
        bdDesc.setTranslation(4, 0);

        const coDesc = ColliderDesc.ball(.3);

        const bd = context.world.createRigidBody(bdDesc);
        const co = context.world.createCollider(coDesc, bd.handle);

        let i = 0;
        setInterval(function() {
            if (i % 2) {
                bd.sleep();
                console.log("sleep");
            }
            else {
                bd.wakeUp();
                console.log("wakeup");
            }
            i++;
        }, 100);

and result:

sleep.mp4

(ball in grey means it's sleeping)

so it just works normally.

[jcyuan]

btw, set world's gravity as 0, the same result. it will blink normally.

[jcyuan]

ah, i know what you mean now, you wanna make it sleeping when it's just created, right?
i think not unless you call bd.sleep() in next frame.

@sebcrozet i think we need to add sleeping in RigidBodyDesc for an initial status?

[sebcrozet]

i think we need to add sleeping in RigidBodyDesc for an initial status?

That’s correct, this needs to be added.

[lo-th]

yes cool
i use 3d version, i test soon 2d
also i note strange collision for block touching ( that why i need know if margin )

[jcyuan]

2d & 3d used the shared code, so it was added for both.

for collision, if you mean penetration, try enable CCD, and limit velocity etc.

[lo-th]

yes thank's i will release my phy engin soon
with oimo ammo physx and yes rapier :)