Adding Entity as child to other entity makes it invisible

[ashirviskas]

Bevy version

0.7.0

[Optional] Relevant system information

OS: Arch Linux
Cargo version: cargo 1.63.0-nightly

2022-06-23T15:29:27.512314Z  INFO bevy_render::renderer: AdapterInfo { name: "AMD RADV RENOIR", vendor: 4098, device: 5708, device_type: IntegratedGpu, backend: Vulkan }

What you did

I tried adding new entities as children to parent entity.

What went wrong

Child entities are invisible, but they still function (as colliders for example).

Additional information

Code that works and renders all entities (only included shortened version for the left wall, but code does the same for all of the walls):

let cell_wall_entity_left = commands
    .spawn()
    .insert_bundle(
        SpriteBundle {
            sprite: Sprite {
                color: Color::rgb(0.5, 0.5, 0.3),
                ..default()
            },
            transform: Transform {
                translation: wall_position.extend(0.1),
                scale: Vec3::new(40., 5. , 1.),
                ..default()
            },
            ..default()
        },
    )
    .insert(Collider)
    .id();
let parent_cell = commands
    .spawn_bundle(CellBundle::new(
        SpriteBundle {
            sprite: Sprite {
                color: cell_type.to_color(),
                ..default()
            },
            transform: Transform {
                translation: cell_position.extend(0.),
                scale: Vec3::new(CELL_SIZE.x, CELL_SIZE.y, 1.0),
                ..default()
            },
            ..default()
        },
        Cell::new(),
        Collider,
    ));

If I change the last line to:

    )).insert(CellType::Cell).push_children(&[cell_wall_entity_left]);

Then it looks like this:

[DJMcNab]

Are you sure it's invisible and not just outside the screen boundaries?

You have requested for the wall to be placed at (CELL_SIZE.x*wall_position.x, CELL_SIZE.y*wall_position.y). I would be surprised if that is within the screenshot area you have given, given its small size.

[tim-blackbird]

Transform defines a position relative to a parent.
So the final position of cell_wall_entity_left is it's Transform plus the Transform of the parent.
The bug here is actually the collider still being in that spot. I believe this is a known issue with bevy_rapier.

[ashirviskas]

You have requested for the wall to be placed at (CELL_SIZE.xwall_position.x, CELL_SIZE.ywall_position.y). I would be surprised if that is within the screenshot area you have given, given its small size.

I might have. So basically you have to use sizes/positions for children relative to the parent. I think I got it now, thank you!

[ashirviskas]

The bug here is actually the collider still being in that spot. I believe this is a known issue with bevy_rapier.

Oh, that might explain it. Any issue I could track?

[tim-blackbird]

Hmm. Looks like this issue should be fixed in version 0.14 of bevy_rapier dimforge/bevy_rapier#172

[ashirviskas]

Huh, I've upgraded to bevy_rapier2d = "0.14.1" but it does not seem fixed as particles can still get through the child walls, even though they're displayed correctly.

[ashirviskas]

My cell wall spawning code and Cell spawning code + adding cell walls as children that does not work as intended. I can now see the walls being rendered properly, but their collider boxes are in the middle of the world and you can see the particles bouncing off of them:

Peek.2022-06-23.20-15.mp4

[tim-blackbird]

Try using the debug-render feature of bevy_rapier2d and fiddle with your code a bit. Can't help much as I'm on my phone right now.

[ashirviskas]

Try using the debug-render feature of bevy_rapier2d and fiddle with your code a bit. Can't help much as I'm on my phone right now.

Thanks for the tips! I enabled debug-render, and refactored child spawning several times, but still no go. It either messes up the Sprite or the Collider position. Can't have both it seems