Function frustum 

pub fn frustum<T>(lbn: &Vector3<T>, rtf: &Vector3<T>) -> Matrix4<T>
where
    T: Scalar,

Creates a perspective projection matrix from frustum bounds.

Parameters

• lbn: Left-bottom-near corner (x, y, z)
• rtf: Right-top-far corner (x, y, z)

The frustum is defined by the near and far clipping planes.