Function perspective 

pub fn perspective<T: FloatScalar>(
    fovy: T,
    aspect: T,
    near: T,
    far: T,
) -> Matrix4<T>

Creates a perspective projection matrix.

Parameters

• fovy: Field of view angle in radians (vertical)
• aspect: Aspect ratio (width / height)
• near: Near clipping plane distance
• far: Far clipping plane distance

Uses the standard OpenGL perspective projection formula.