Migration guide:
# Objective
Currently there seems to be no way to enable picking through
render-to-texture cameras
## Solution
This PR allows casting rays from the game code quite easily.
## Testing
- I've tested these in my game and it seems to work
- I haven't tested edge cases
---
## Showcase
<details>
<summary>Click to view showcase</summary>
```rust
fn cast_rays_from_additional_camera(
cameras: Query<(&GlobalTransform, &Camera, Entity), With<RenderToTextureCamera>>,
mut rays: ResMut<RayMap>,
pointers: Query<(&PointerId, &PointerLocation)>,
) {
for (camera_global_transform, camera, camera_entity) in &cameras {
for (pointer_id, pointer_loc) in &pointers {
let Some(viewport_pos) = pointer_loc.location() else {
continue;
};
// if camera result is transformed in any way, the reverse transformation
// should be applied somewhere here
let ray = camera
.viewport_to_world(camera_global_transform, viewport_pos.position)
.ok();
if let Some(r) = ray {
rays.map.insert(RayId::new(camera_entity, *pointer_id), r);
}
}
}
}
```
</details>
## Migration Guide
The `bevy_picking::backend::ray::RayMap::map` method is removed as
redundant,
In systems using `Res<RayMap>` replace `ray_map.map()` with
`&ray_map.map`