def test_homogenize(self): coords = [[1.0, 1.0], [0.5, -0.25], [100.0, -50.0]] hcoords = [[1.0, 1.0, 1.0], [0.5, -0.25, 1.0], [100.0, -50.0, 1.0]] homogenized = geometry.homogenize(tf.constant(coords)) dehomogenized = geometry.dehomogenize(homogenized) scale = tf.constant([10.0, 0.2, .5], shape=[3, 1]) dehomogenized2 = geometry.dehomogenize(homogenized * scale) self.assertAllClose(homogenized, hcoords) self.assertAllClose(dehomogenized, coords) self.assertAllClose(dehomogenized2, coords)
def test_mat34_transform_planes(self):
# Some planes...
planes = tf.convert_to_tensor([[1.0, 2.0, 3.0, 4.0],
[0.5, 0.3, 0.1, 0.0],
[0.0, 1.0, 0.0, 100.0],
[-1.0, 0.0, -1.0, 0.25]])
# ...and some points
points = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]]
# (Since we know it's all linear, four planes and three
# points are enough to span all possibilities!)
i = [[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0]]
m = [[1.0, 0.0, 0.0, 4.0], [0.0, 0.0, -1.0, 5.0], [0.0, 1.0, 0.0, 6.0]]
# Identity transform doesn't change the planes:
input_planes = tf.constant(planes)
identity_planes = geometry.mat34_transform_planes(
tf.constant(i), input_planes)
self.assertAllEqual(identity_planes, planes)
# Transform and inverse transform is the identity:
self.assertAllEqual(
geometry.mat34_transform_planes(
tf.constant(m),
geometry.mat34_transform_planes(
geometry.mat34_pose_inverse(tf.constant(m)),
input_planes)), planes)
# Dot products between planes and points are preserved (since
# m doesn't change scale):
input_points = tf.constant(points)
dot_products = tf.matmul(geometry.homogenize(input_points),
planes,
transpose_b=True)
transformed_planes = geometry.mat34_transform_planes(
tf.constant(m), input_planes)
transformed_points = geometry.mat34_transform(tf.constant(m),
input_points)
transformed_dot_products = tf.matmul(
geometry.homogenize(transformed_points),
transformed_planes,
transpose_b=True)
self.assertAllClose(dot_products, transformed_dot_products)