How do I draw arbitrary things on top of UI?

[nicopap]

This is an often asked question, I've an answer, but it is confined to the depths of the discord server, so I'm reproducing it here for search-engine visibility.

I want to draw a texture, a 3D mesh, a minimap… anything! on top of the bevy UI. How do I do this?

[nicopap]

As of bevy 0.12

1. Spawn a camera with the UiCameraConfig { show_ui: false } component on the same entity.
2. Set the Camera::order field of the camera to something higher than the main one
3. Give the camera a RenderLayers of whatever
4. Give whatever you want to draw on top of UI a RenderLayers component intersecting with that of the camera.

[mirsella]

Update for bevy 0.14:

• the root ui node should have the TargetCamera component as UiCameraConfig doesn't exist anymore
• on the new camera add camera2.camera.clear_color = ClearColorConfig::None; so that it's transparent, and the ui is shown behind. (without it, the screen is gray)