def test_perspective_camera(self):
cam = PerspectiveCamera(screen_distance=1.0, aspect_ratio=2.0)
# Fire one ray for each corner of the image plane
ray1 = cam.fire_ray(0.0, 0.0)
ray2 = cam.fire_ray(1.0, 0.0)
ray3 = cam.fire_ray(0.0, 1.0)
ray4 = cam.fire_ray(1.0, 1.0)
# Verify that all the rays depart from the same point
assert ray1.origin.is_close(ray2.origin)
assert ray1.origin.is_close(ray3.origin)
assert ray1.origin.is_close(ray4.origin)
# Verify that the ray hitting the corners have the right coordinates
assert ray1.at(1.0).is_close(Point(0.0, 2.0, -1.0))
assert ray2.at(1.0).is_close(Point(0.0, -2.0, -1.0))
assert ray3.at(1.0).is_close(Point(0.0, 2.0, 1.0))
assert ray4.at(1.0).is_close(Point(0.0, -2.0, 1.0))
def test_perspective_camera_transform(self):
cam = PerspectiveCamera(transformation=translation(-VEC_Y * 2.0) *
rotation_z(pi / 2.0))
ray = cam.fire_ray(0.5, 0.5)
assert ray.at(1.0).is_close(Point(0.0, -2.0, 0.0))