Function glm::ext::perspective

pub fn perspective<T>(fov_y: T, aspect: T, z_near: T, z_far: T) -> Matrix4<T> where
    T: BaseFloat, 

Creates a matrix for a symetric perspective-view frustum based on the default handedness.

fov_y is the field of view angle in the y direction in radians. The aspect ratio determines the field of view in the x direction. near_z is the distance from the viewer to the near clipping plane (always positive) and far_z is the distance from the viewer to the far clipping plane (always positive).