Default Scale is Zero -- Lint for footguns?

[JosephCatrambone]

I was having problems with the following code:

	let mut ssb = SpriteSheetBundle {
		sprite: TextureAtlasSprite::new(0),
		texture_atlas: sprite_sheets.player.clone(),
		transform: Transform { // Eyes here!
			translation: Default::default(),
			rotation: Default::default(),
			scale: Default::default()
		},
		global_transform: Default::default(),
		visibility: Default::default(),
		computed_visibility: Default::default()
	};

I thought at first that the player was being drawn past the camera FAR, but this turned out not to be the case. No matter what I did with the Z-depth, I couldn't make the character appear. This, however, worked fine.

	let mut ssb = SpriteSheetBundle {
		sprite: TextureAtlasSprite::new(0),
		texture_atlas: sprite_sheets.player.clone(),
		transform: Default::default(), // Eyes here!
		global_transform: Default::default(),
		visibility: Default::default(),
		computed_visibility: Default::default()
	};

Ultimately, it turns out that the problem was nothing to do with the transform and everything to do with the default scale, which is 0,0,0, making the sprite invisible.

Since scale is a Vec3 I don't think we can change the 'default' for just that type, but perhaps there can be a lint or a debug-only message which helps people who spawn something with a default scale of all zeros?

[MrGVSV]

Not related to the linting portion of this, but it's probably recommended to use ..default() (or ..Default::default()) for defaulting parts of components/bundles. That way, you get the actual defaults as specified by the struct.

[JosephCatrambone]

I was replacing parts of the transform. The actual bit was

let mut ssb = SpriteSheetBundle {
		sprite: TextureAtlasSprite::new(0),
		texture_atlas: sprite_sheets.player.clone(),
		transform: Transform { // Eyes here!
			translation: Vec3::new(x, y, PLAYER_RENDER_PRIORITY),
			rotation: Default::default(),
			scale: Default::default()
		},
		global_transform: Default::default(),
		visibility: Default::default(),
		computed_visibility: Default::default()
	};

[tim-blackbird]

You could write that like so:

Transform {
    translation: Vec3::new(x, y, PLAYER_RENDER_PRIORITY),
    ..Default::default(),
},

Or, using from_xyz.

Transform::from_xyz(x, y, PLAYER_RENDER_PRIORITY),

[NiklasEi]

The same pattern works for the whole bundle. As far as I see, you only need to set two fields.

[afonsolage]

There is a unofficial crate for bevy linting: https://github.com/MinerSebas/bevy_lint, but linting at this point of Bevy is very tough work, since API will be changed a lot.

When we got the Bevy Editor I think this kind o problem will be easier to track down, since one could just inspect why the mesh/sprite/UI isn't being rendered.