Sprite tracking cursor jitters when panning camera

[liamaharon]

I want a sprite to track the cursor when "placing" it, any ideas why it jitters when I pan the camera? It doesn't jitter when I move the cursor.

The system to update the Sprite transform looks like this:

 fn update_shadow_to_cursor(
    windows: Query<&Window, With<PrimaryWindow>>,
    cams: Query<(&Camera, &GlobalTransform), With<Camera2d>>,
    mut q: Query<&mut Transform, With<ColonyShadowMarker>>,
) {
    let window = windows.single().unwrap();
    let (cam, cam_transform) = cams.single().unwrap();

    if let Some(screen_pos) = window.cursor_position() {
        if let Ok(world_pos) = cam.viewport_to_world_2d(cam_transform, screen_pos) {
            let mut t = q.single_mut().unwrap();
            t.translation = world_pos.extend(t.translation.z);
        }
    }
}

and I am running it in PostUpdate after TransformSystem::TransformPropagate.

My pan logic runs in Update.

Thanks a lot!

Screen_Recording_2025-09-28_at_13.04.51.mov

[liamaharon]

@gμ helped me resolve this on Discord.

I needed to use the cam Transform (not GlobalTransform), and then run the system .before(TransformSystem::TransformPropagate) instead of .after.