def ortho_matrix(aspect, near, far, width):
"""
Camera frustum looks along -Z axis.
Result frustum camera looks along -Z axis, like in OpenGL.
"""
height = aspect * width
P = transformations.clip_matrix(-width/2, width/2, -height/2, height/2, near, far, perspective=False)
P = np.dot(P, scale_matrix([1, 1, -1]))
return np.float32(P)
def perspective_matrix(aspect, near, far, fov_h=45):
"""
Camera frustum looks along -Z axis.
Result frustum camera looks along -Z axis, like in OpenGL.
"""
tan = np.tan(np.radians(fov_h) / 2)
right = tan * near
left = -right
bottom, top = aspect * left, aspect * right
P = transformations.clip_matrix(left, right, bottom, top, near, far, perspective=True)
P = np.dot(P, scale_matrix([1, 1, -1]))
return np.float32(-P)
