collider_active_hooks

Physics hooks are user-defined callbacks used to filter-out some contact pairs, or modify contacts, based on arbitrary user code. In order to enable a physics hook for a pair of colliders, at least one of the involved colliders must have the corresponding hook set as active. A hook is activated for a collider by setting its corresponding active hooks bit to 1:

• Setting the ActiveHooks::FILTER_CONTACT_PAIRActiveHooks.FILTER_CONTACT_PAIR bit to 1 enables the manual filtering of all the contact pairs involving the collider.
• Setting the ActiveHooks::FILTER_INTERSECTION_PAIRActiveHooks.FILTER_INTERSECTION_PAIRbit to 1 enables the manual filtering of all the contact pairs involving the collider. - Setting the ActiveHooks::MODIFY_SOLVER_CONTACTS bit to 1 enables the manual contact modification for all the contact manifolds involving the collider.

The active hooks of a collider can be set when the collider is created or after its creation:

/* Set the active hooks when the collider is created. */
let collider = ColliderBuilder::ball(0.5)
    .active_hooks(ActiveHooks::FILTER_CONTACT_PAIRS | ActiveHooks::MODIFY_SOLVER_CONTACTS)
    .build();

/* Set the active hooks after the collider creation. */
let collider = collider_set.get_mut(collider_handle).unwrap();
collider
    .set_active_hooks(ActiveHooks::FILTER_CONTACT_PAIRS | ActiveHooks::MODIFY_SOLVER_CONTACTS);
assert!(collider
    .active_hooks()
    .contains(ActiveHooks::FILTER_CONTACT_PAIRS));
assert!(collider
    .active_hooks()
    .contains(ActiveHooks::MODIFY_SOLVER_CONTACTS));

/* Set the active hooks when the collider is created. */
commands
    .spawn(Collider::ball(0.5))
    .insert(ActiveHooks::FILTER_CONTACT_PAIRS | ActiveHooks::MODIFY_SOLVER_CONTACTS);

/* Set the active hooks inside of a system. */
fn modify_collider_active_hooks(mut active_hooks: Query<&mut ActiveHooks>) {
    for mut active_hooks in active_hooks.iter_mut() {
        *active_hooks = ActiveHooks::FILTER_CONTACT_PAIRS | ActiveHooks::MODIFY_SOLVER_CONTACTS;
    }
}

/* Set the active hooks when the collider is created. */
let colliderDesc = RAPIER.ColliderDesc.ball(0.5)
    .setActiveHooks(RAPIER.ActiveHooks.FILTER_CONTACT_PAIRS);
let collider = world.createCollider(colliderDesc);

/* Set the active hooks after the collider creation. */
collider.setActiveHooks(RAPIER.ActiveHooks.FILTER_CONTACT_PAIRS);