def test_rotate_point_y(self):
p = Point(0, 0, 1)
half_quarter = Transformations.rotation_y(math.pi / 4)
full_quarter = Transformations.rotation_y(math.pi / 2)
self.assertEqual(Matrix.multiply_tuple(half_quarter, p),
Point(math.sqrt(2) / 2, 0,
math.sqrt(2) / 2))
self.assertEqual(Matrix.multiply_tuple(full_quarter, p),
Point(1, 0, 0))
def test_tranforming_bounding_box(self):
box = Bounds(Point(-1, -1, -1), Point(1, 1, 1))
matrix = Transformations.rotation_x(math.pi / 4).dot(
Transformations.rotation_y(math.pi / 4))
box2 = box.transform(matrix)
self.assertEqual(box2.min, Point(-1.4142, -1.7071, -1.7071))
self.assertEqual(box2.max, Point(1.4142, 1.7071, 1.7071))
def test_ray_camera_transformed(self):
c = Camera(201, 101, math.pi / 2)
c.transform = Transformations.rotation_y(math.pi / 4).dot(
Transformations.translation(0, -2, 5))
r = Camera.ray_for_pixel(c, 100, 50)
self.assertEqual(r.origin, Point(0, 2, -5))
self.assertEqual(r.direction,
Vector(math.sqrt(2) / 2, 0, -math.sqrt(2) / 2))
def test_converting_normal_from_object_to_world_space(self):
g1 = Group()
g1.transform = Transformations.rotation_y(math.pi / 2)
g2 = Group()
g2.transform = Transformations.scaling(1, 2, 3)
g1.add_child(g2)
s = Sphere()
s.transform = Transformations.translation(5, 0, 0)
g2.add_child(s)
n = s.normal_to_world(Vector(math.sqrt(3) /3, math.sqrt(3) / 3, math.sqrt(3) / 3))
self.assertEqual(n, Vector(0.2857, 0.4286, -0.8571))
def test_converting_point_from_world_to_object_space(self):
g1 = Group()
g1.transform = Transformations.rotation_y(math.pi / 2)
g2 = Group()
g2.transform = Transformations.scaling(2, 2, 2)
g1.add_child(g2)
s = Sphere()
s.transform = Transformations.translation(5, 0, 0)
g2.add_child(s)
p = s.world_to_object(Point(-2, 0, -10))
self.assertEqual(p, Point(0, 0, -1))
def test_finding_normal_on_child_object(self):
g1 = Group()
g1.transform = Transformations.rotation_y(math.pi / 2)
g2 = Group()
g2.transform = Transformations.scaling(1, 2, 3)
g1.add_child(g2)
s = Sphere()
s.transform = Transformations.translation(5, 0, 0)
g2.add_child(s)
n = s.normal_at(Point(1.7321, 1.1547, -5.5774))
self.assertEqual(n, Vector(0.2857, 0.4286, -0.8571))
from tuple import Point, Vector
from world import World
if __name__ == '__main__':
# The floor is an extremely flattened sphere with a matte texture
floor = Sphere()
floor.transform = Transformations.scaling(10, 0.1, 10)
floor.material = Material()
floor.material.color = Color(1, 0.9, 0.9)
floor.material.specular = 0
# The wall on the left has the same scale and color as the floor, but is also rotated and translated into place
left_wall = Sphere()
left_wall.transform = Transformations.translation(0, 0, 5)
left_wall.transform = left_wall.transform.dot(
Transformations.rotation_y(-math.pi / 4))
left_wall.transform = left_wall.transform.dot(
Transformations.rotation_x(math.pi / 2))
left_wall.transform = left_wall.transform.dot(
Transformations.scaling(10, 0.1, 10))
left_wall.material = floor.material
# The wall on the right is identical to the left wall, but is rotated the opposite direction in y
right_wall = Sphere()
right_wall.transform = Transformations.translation(0, 0, 5)
right_wall.transform = right_wall.transform.dot(
Transformations.rotation_y(math.pi / 4))
right_wall.transform = right_wall.transform.dot(
Transformations.rotation_x(math.pi / 2))
right_wall.transform = right_wall.transform.dot(
Transformations.scaling(10, 0.1, 10))
