Sprite z-order is wrong when parent entity has no Transform.

[StarArawn]

Bevy version

0.5

Operating system & version

Windows 10

What you did

Create a sprite like:

commands
        .spawn()
        .insert(Enemy::default())
        .with_children(|child_builder| {
            let texture_handle: Handle<Texture> = asset_server.load("textures/spider_sprite.png");
            let enemy_sprite_material = materials.add(texture_handle.into());
            child_builder    
                .spawn_bundle(SpriteBundle {
                    material: enemy_sprite_material,
                    transform: Transform::from_xyz(position.x, position.y, 10.0),
                    ..Default::default()
                })
                .insert(RenderLayers::layer(0));
        })

Have another sprite that is suppose to render behind and you can see how the sprites z values on the GPU are completely wrong.

With a sprite that has no parent the calculated z values are:
.9980
and with a sprite that has a parent without a transform:
-0.001

What you expected to happen

If a parent entity has no transform its children's transforms should not change.

[tim-blackbird]

The given example code will now produce a warning since #5590 was merged

[superdump]

@StarArawn - is this still a problem?

[nicopap]

It is "fixed" by #5590 in the sense that it now displays a warning that tells the user why the transform is not applied, and allow them to fix it themselves.

[nicopap]

should this be kept open or can we consider it resolved?

[TimJentzsch]

Triage

Behavior is unchanged with Bevy 0.12.

Reproduction code: https://github.com/TimJentzsch/bevy_triage/tree/main/issues/issue_1976

In this example we spawn a yellow rectangle at the bottom, a red rectangle in the middle, but with a parent element which doesn't have a transform, and a blue rectangle at the top.
Instead, the red rectangle is at the bottom:

However, we get the following warnings in the console:

2024-01-25T19:44:31.856051Z  WARN bevy_hierarchy::valid_parent_check_plugin: warning[B0004]: An entity with the InheritedVisibility component has a parent without InheritedVisibility.
This will cause inconsistent behaviors! See https://bevyengine.org/learn/errors/#b0004
2024-01-25T19:44:31.856091Z  WARN bevy_hierarchy::valid_parent_check_plugin: warning[B0004]: An entity with the GlobalTransform component has a parent without GlobalTransform.
This will cause inconsistent behaviors! See https://bevyengine.org/learn/errors/#b0004

Considering that there is even an error code with a more detailed explanation, I think we could consider this resolved for now.
I will defer for other maintainers to make this decision though.

[mnmaita]

Since we can always reopen this in the future, I'm closing this as completed based on the fact that we have these warnings now.