Post-process vignette effect

We’ve added vignette, which is a common post-processing effect that creates a reduction of image brightness towards the periphery compared to the image center. It’s often used to draw focus to the center of the screen or to simulate the look of a camera lens.

To use it, add the Vignette component to your camera:

commands.spawn((
    Camera3d::default(),
    Vignette::default()
))