def test_transformation_matrix_for_the_default_orientation(self):
from_where = point(0, 0, 0)
to = point(0, 0, -1)
up = vector(0, 1, 0)
t = view_transform(from_where, to, up)
self.assert_matrix_equals(identity_matrix, t)
def test_the_view_trasnformation_move_the_world(self):
from_where = point(0, 0, 8)
to = point(0, 0, 0)
up = vector(0, 1, 0)
t = view_transform(from_where, to, up)
self.assert_matrix_equals(translation(0, 0, -8), t)
def test_view_transformation_matrix_looking_in_positive_z_direction(self):
from_where = point(0, 0, 0)
to = point(0, 0, 1)
up = vector(0, 1, 0)
t = view_transform(from_where, to, up)
self.assertEqual(scaling(-1, 1, -1), t)
def test_arbitrary_view_transformation(self):
from_where = point(1, 3, 2)
to = point(4, -2, 8)
up = vector(1, 1, 0)
t = view_transform(from_where, to, up)
m = Matrix4(-0.50709, 0.50709, 0.67612, -2.36643, 0.76772, 0.60609,
0.12122, -2.82843, -0.35857, 0.59761, -0.71714, 0.00000,
0.00000, 0.00000, 0.00000, 1.00000)
self.assert_matrix_equals(m, t)
def test_rendering_world_with_camera(self):
w = default_world()
c = Camera(11, 11, pi / 2.0)
from_where = point(0, 0, -5)
to = point(0, 0, 0)
up = vector(0, 1, 0)
c.transform = view_transform(from_where, to, up)
image = render(c, w)
self.assert_tuple_equals(color(0.38066, 0.47583, 0.2855),
image.pixel_at(5, 5), 0.001)
middle.material.color = color(0.1, 1, 0.5)
middle.material.ambient = 0.1
middle.material.diffuse = 0.7
middle.material.specular = 0.3
right = Sphere()
right.transform = translation(1.5, 0.5, -0.5) * scaling(0.5, 0.5, 0.5)
right.material.color = color(0.5, 1, 0.1)
right.material.diffuse = 0.7
right.material.specular = 0.3
left = Sphere()
left.transform = translation(-1.5, 0.33, -0.75) * scaling(0.33, 0.33, 0.33)
left.material.color = color(1, 0.8, 0.1)
left.material.diffuse = 0.7
left.material.specular = 0.3
light_position = point(-10, 10, -10)
light_color = color(1, 1, 1)
light = PointLight(light_position, light_color)
world = World(light=light,
objects=[left, right, middle, left_wall, right_wall, floor])
camera = Camera(200, 100, pi / 3)
camera.transform = view_transform(point(0, 1.5, -5), point(0, 1, 0),
vector(0, 1, 0))
r = render(camera, world)
r.save_to_file('scene2.ppm')