Colliders don't work without rigid body

[SUPERCILEX]

I only need colliders and none of the other physics stuff. It the correct way to get child colliders working to use a fixed rigid body? Or can it be made so child colliders still work without the parent having a rigid body component? The old version handled this as far as I can tell.

[sebcrozet]

Hi! Colliders without parents attached should still work. Did you set the proper ActiveCollisionTypes?

[SUPERCILEX]

Hmmm, no I didn't use ActiveCollisionTypes. Should we be using STATIC_STATIC maybe?

BTW, I'm not quite sure what you mean by "without parents attached." This is the code we're using:

    commands
        .spawn()
        .insert(MAIN_BAG_COLLIDER.clone())
        .insert(Sensor(true))
        .insert(BAG_COLLIDER_GROUP)
        .insert(RigidBody::Fixed) // Adding this line makes the with_children colliders work. Otherwise, they don't seem to do anything.
        .with_children(|parent| {
            parent
                .spawn()
                .insert(BOUNDARY_BAG_COLLIDER.clone())
                .insert(Sensor(true))
                .insert(BAG_BOUNDARY_COLLIDER_GROUP);

            parent
                .spawn()
                .insert(LID_BAG_COLLIDER.clone())
                .insert(Sensor(true))
                .insert(BAG_LID_COLLIDER_GROUP);
        })

[sebcrozet]

That's correct: STATIC_STATIC is the one.
By no parent attached I meat no rigid-body attached. I did not mean "parent" as in the Bevy parent entity.

[SUPERCILEX]

Ok, just tried insert(ActiveCollisionTypes::STATIC_STATIC) on all my colliders but no dice.

[sebcrozet]

Ah, that’s unfortunate. Perhaps we have a bug then. Do you have a minimal piece of code to reproduce the problem (your code above does show how the colliders are initialized, but not what you expect them to do)?
Also: if you enable the debug-renderer, with .add_plugin(RapierDebugRenderPlugin::default()), do you see that these colliders are rendered or not?

[SUPERCILEX]

We've been using the colliders like this:

 let foo = rapier_context
        .intersection_with_shape(
            collider_transform.translation,
            collider_transform.rotation,
            collider,
            BAG_BOUNDARY_COLLIDER_GROUP.into(),
            None,
        );

Unfortunately I can't check the debug renderer because of #157 presumably (we're using the OrthographicCameraBundle::new_2d()).

[agdt3]

For reference, I'm also getting this issue. Without adding a RigidBody::Dynamic to at least one of the colliders, nothing shows up in the intersection graph for a Sensor or the contact graph for non-Sensor colliders. Events don't show up at all regardless of the body type or the ActiveEvents flags that I set.

Cargo:

bevy = { version = "0.8.0", features = ["dynamic"] }
bevy_rapier2d = { version = "0.17.0", features = ["debug-render"] }
rand = "0.8.5"

[Fidius-jko]

Take event2 example and change rigid body to non dynamic and move it with bevy inspector egui

Ah, that’s unfortunate. Perhaps we have a bug then. Do you have a minimal piece of code to reproduce the problem (your code above does show how the colliders are initialized, but not what you expect them to do)? Also: if you enable the debug-renderer, with .add_plugin(RapierDebugRenderPlugin::default()), do you see that these colliders are rendered or not?