UI components not respecting RenderLayers

[paulkre]

The visibility of UI entities like text is not affected by the RenderLayers component. This is a problem when trying to prerender a scene with RenderTarget::Image to use it as a mesh texture (the game UI will also be visible on the texture).

Is there a way to make UI components respect RenderLayers?

[paulkre]

I modified the render_to_texture example to demonstrate the bug:
https://github.com/paulkre/bevy/blob/ui-renderlayers-demo/examples/3d/render_to_texture.rs

bevy-ui-renderlayers-demo.mp4

[paulkre]

I just found an acceptable workaround. You can add the UiCameraConfig { show_ui: false } component to your RenderTarget::Image-camera which hides all UI elements for that camera. This helps most of the time but sometimes you might want to render different UI elements in both cameras. In these situations it would be great if RenderLayers worked for UI.

[jdm]

Updated example change that demonstrates the issue:

diff --git a/examples/3d/render_to_texture.rs b/examples/3d/render_to_texture.rs
index 81c687e5a..e4473bcae 100644
--- a/examples/3d/render_to_texture.rs
+++ b/examples/3d/render_to_texture.rs
@@ -35,6 +35,7 @@ fn setup(
     mut meshes: ResMut<Assets<Mesh>>,
     mut materials: ResMut<Assets<StandardMaterial>>,
     mut images: ResMut<Assets<Image>>,
+    asset_server: Res<AssetServer>,
 ) {
     let size = Extent3d {
         width: 512,
@@ -141,6 +142,17 @@ fn setup(
         transform: Transform::from_xyz(0.0, 0.0, 15.0).looking_at(Vec3::ZERO, Vec3::Y),
         ..default()
     });
+
+    commands.spawn((
+        TextBundle::from_section(
+            "hello\nbevy!",
+            TextStyle {
+                font: asset_server.load("fonts/FiraSans-Bold.ttf"),
+                font_size: 200.0,
+                color: Color::RED,
+            },
+        ),
+    ));
 }

 /// Rotates the inner cube (first pass)

[musjj]

Hmmm, when I added UiCameraConfig { show_ui: false } to the camera looking at the rendered image, the UI simply does not get rendered.

Adding it to the camera rendering to the image using RenderTarget simply does nothing. Did anything change in 0.12?

[Aunmag]

Same problem. I use two cameras: one for classic game rendering, and second for rendering onto tile map (decals like blood texures, etc..). But when I spawn a TextBundle it renders to screen (which is ok) and to all my tiles (which is bad).

Here's how I spawn text:

world.spawn(
    TextBundle::from_sections([
        TextSection::new("FPS: ", style.clone()),
        TextSection::from_style(style.clone()),
        TextSection::new("\nEntities: ", style.clone()),
        TextSection::from_style(style.clone()),
        TextSection::new("\nAudio sources: ", style.clone()),
        TextSection::from_style(style.clone()),
        TextSection::new(
            "\n\
            \nSpawn weapon: [G]\
            \nSpawn human : [H] group: [+SHIFT]\
            \nSpawn zombie: [J] group: [+SHIFT]\
            ",
            style,
        ),
    ])
);

Here's how I spawn second camera (for tile map blending):

commands
    .spawn(Camera2dBundle {
        camera: Camera {
            target: RenderTarget::Image(target),
            output_mode: CameraOutputMode::Write {
                blend_state: Some(BlendState::PREMULTIPLIED_ALPHA_BLENDING),
                color_attachment_load_op: LoadOp::Load,
            },
            ..Default::default()
        },
        camera_2d: Camera2d {
            clear_color: ClearColorConfig::None,
        },
        transform,
        ..Default::default()
    })
    .insert(RenderLayers::layer(1)); // NOTE: used different render layer

But thanks to @paulkre workaround with UiCameraConfig helped!

[vladbat00]

Seems like the UiTargetCamera addresses the use-case of rendering different UI nodes to different cameras: https://docs.rs/bevy/latest/bevy/prelude/struct.UiTargetCamera.html. Its UX is a bit different from render layers, as it's impossible to render a single UI node to more than one camera but I'd argue it's not something most users would want anyway.