Crash in 3d when the collision shape has no depth

[fgadaleta]

Running this demo (no changes made) https://github.com/jcornaz/heron/blob/main/examples/demo.rs

I get this

thread 'Compute Task Pool (0)' panicked at 'assertion failed: proxy.aabb.maxs[dim] >= self.min_bound', /home/frag/.cargo/registry/src/github.com-1ecc6299db9ec823/rapier3d-0.11.1/src/geometry/broad_phase_multi_sap/sap_axis.rs:55:13

[jcornaz]

I don't reproduce it yet.

Can you please provide more information? The exact commit at which you tried. What is your OS, rust version, and rendering backend?

Can you share the full call stack?

Don't hesitate to provide any additional information you can think of.

[fgadaleta]

I made the ball collide with the ground and it crashes
Please find it here https://github.com/fgadaleta/herontest

[jcornaz]

I see here that you are using the 3d version.

But that example is a 2d example that creates collision shapes without any depth:

• https://github.com/fgadaleta/herontest/blob/main/src/main.rs#L37
• https://github.com/fgadaleta/herontest/blob/main/src/main.rs#L63

And rapier (not heron) crashes when the collision shape has a volume <= 0.

To solve your problem you can either:

• Use non-zero depth for the collision shapes
• Use the 2d feature flag instead of the 3d

[jcornaz]

I leave this issue open for discussion about how we could improve the situation.

On top of my head I think we could:

• ask rapier if it would be possible to not crash for empty volumes
• fail faster, when the shape is created, rather than when it collides
• force the user to deal with shape creation failure by having the factory methods return a Result<CollisionShape, Error>
• document better and warn the user about this limitation

[fgadaleta]

That also happens in 3D where there should be a volume already. For the record, this crashes too:

                    commands
                    .entity(entity)
                    .insert_bundle((transform, GlobalTransform::default()))
                    .insert(RigidBody::Dynamic)
                    .insert(CollisionShape::Sphere { radius: 2.7 })
                    .insert(PhysicMaterial {
                        restitution: 0.7,
                        density: 1.0,
                        ..Default::default()
                    })
                    .insert(CollisionLayers::new(Layer::Player, Layer::Player))
                    .insert(Velocity::from(Vec2::X * 300.0)
                            .with_angular(AxisAngle::new(Vec3::Y, -3.14)))
                    .insert(Drone);

[jcornaz]

That also happens in 3D where there should be a volume already. For the record, this crashes too:

This is only the ball, you also need to give a depth to the ground.

[fgadaleta]

I see here that you are using the 3d version.

But that example is a 2d example that creates collision shapes without any depth:

* https://github.com/fgadaleta/herontest/blob/main/src/main.rs#L37

* https://github.com/fgadaleta/herontest/blob/main/src/main.rs#L63

And rapier (not heron) crashes when the collision shape has a volume <= 0.

To solve your problem you can either:

* Use non-zero depth for the collision shapes

* Use the `2d` feature flag instead of the `3d`

you are right. Changing flag to 2d does not crash and it actually works (the green ball crashes but in a good way lol)

[fgadaleta]

In my example I spawn a dynamic body like so:

                    commands
                    .entity(entity)
                    .insert_bundle((transform, GlobalTransform::default()))
                    .insert(RigidBody::Dynamic)
                    .insert(CollisionShape::Cuboid {
                        half_extends: Vec3::new(1., 1., 1.),
                        border_radius: Some(1.),
                    })
                    .insert(PhysicMaterial {
                        restitution: 0.7,
                        density: 1.0,
                        ..Default::default()
                    })
                    .insert(CollisionLayers::new(Layer::Player, Layer::Player))
                    .insert(Velocity::from(Vec2::X * 300.0)
                            .with_angular(AxisAngle::new(Vec3::Y, -3.14)))
                    .insert(Drone);

and all the rest is static, like so:

                commands
                .entity(entity)
                .insert(RigidBody::Static)
                .insert(CollisionShape::Cuboid {
                    half_extends: Vec3::new(1., 1., 1.),
                    border_radius: Some(1.),
                })
                .insert(PhysicMaterial {
                    restitution: 30.,
                    friction: 1.0,
                    density: 100.0,
                    ..Default::default()
                })
                .insert(CollisionLayers::new(Layer::World, Layer::World))
                ;

[fgadaleta]

That also happens in 3D where there should be a volume already. For the record, this crashes too:

This is only the ball, you also need to give a depth to the ground.

    // The ground
    let size = Vec2::new(1000.0, 50.0);
    commands
        // Spawn a bundle that contains at least a `GlobalTransform`
        .spawn_bundle(SpriteBundle {
            sprite: Sprite {
                color: Color::WHITE,
                custom_size: Some(size),
                ..Default::default()
            },
            transform: Transform::from_translation(Vec3::new(0.0, -300.0, 0.0)),
            ..Default::default()
        })
        // Make it a rigid body
        .insert(RigidBody::Static)
        // Attach a collision shape
        .insert(CollisionShape::Cuboid {
            half_extends: size.extend(2.5) / 2.0,
            border_radius: None,
        })
        // Define restitution (so that it bounces)
        .insert(PhysicMaterial {
            restitution: 0.5,
            ..Default::default()
        });

    // The Ball
    let size = Vec2::new(30.0, 30.0);
    commands
        // Spawn a bundle that contains at least a `GlobalTransform`
        .spawn_bundle(SpriteBundle {
            sprite: Sprite {
                color: Color::GREEN,
                custom_size: Some(size),
                ..Default::default()
            },
            transform: Transform::from_translation(Vec3::new(-400.0, 200.0, 0.0)),
            ..Default::default()
        })
        // Make it a rigid body
        .insert(RigidBody::Dynamic)
        // Attach a collision shape
        .insert(CollisionShape::Cuboid {
            half_extends: size.extend(2.5) / 2.0,
            border_radius: None,
        })
        // Add an initial velocity. (it is also possible to read/mutate this component later)
        .insert(Velocity::from(Vec2::Y * -300.0).with_angular(AxisAngle::new(Vec3::Z, -PI)))
        // Define restitution (so that it bounces)
        .insert(PhysicMaterial {
            restitution: 0.7,
            ..Default::default()
        });

Collision is logged but ball disappears from screen (without actually colliding).
Using feature = ['3d'] here
2d in Cargo.toml works better (kinda)