Function paint_see_through 

pub fn paint_see_through(
    scene: &mut Scene,
    transform: Affine,
    rect: Rect,
    radius: f64,
    theme: &Theme,
) -> Theme

Paint the see-through material over rect at radius: half the panel ground over the blurred backdrop, its floating shadow outside it only (a shadow under the body would darken what shows through) and the floating hairline. Only for chrome over pixels the person is choosing (docs/design-language.md, “Material and transparency”). Returns the theme a child standing on it paints with.