Struct Cell 

pub struct Cell<'a> {
    pub layer: &'a LayerNode,
    pub scene: &'a Scene3d,
    pub parent: Option<usize>,
    pub hole: Option<(usize, Rect)>,
    pub doorway: Mat4,
    pub to_parent: Mat4,
}

A space a scene opens.

Fields

layer: &'a LayerNode

The scene’s layer.

scene: &'a Scene3d

The scene.

parent: Option<usize>

The space its doorway lies in; None for the window’s scene.

hole: Option<(usize, Rect)>

The surface of the parent space whose content holds the doorway, by its number among the tree’s surfaces, and the doorway’s rect in that content, when the doorway lies flat in it.

doorway: Mat4

Places the unit square on the doorway in the parent space, the space lying beyond it along its z; the identity for the window’s scene.

to_parent: Mat4

Maps the space into its parent’s.