def test_reference_smoothing_hexagon():
"""
This is a simple test of our laplacian_smoothing reference function.
Try 'smoothing' a simple 2D hexagon, which is an easy case to understand.
"""
# This map is correctly labeled with the vertex indices
_ = -1
hexagon = [[[_,_,_,_,_,_,_],
[_,_,0,_,1,_,_],
[_,_,_,_,_,_,_],
[_,2,_,3,_,4,_],
[_,_,_,_,_,_,_],
[_,_,5,_,6,_,_],
[_,_,_,_,_,_,_]]]
hexagon = 1 + np.array(hexagon)
original_vertices = np.transpose(hexagon.nonzero())
faces = [[3,1,4],
[3,4,6],
[3,6,5],
[3,5,2],
[3,2,0],
[3,0,1]]
vertices = laplacian_smooth(original_vertices, faces, 1)
# Since vertex 3 is exactly centered between the rest,
# its location never changes.
assert (vertices[3] == original_vertices[3]).all()
def test_reference_smoothing_trivial():
"""
This is a simple test of our laplacian_smoothing reference function.
"""
vertices = np.array([[0.0, 0.0, 0.0], [0.0, 0.0, 1.0], [0.0, 0.0, 2.0]])
# This "face" is actually straight line,
# which makes it easy to see what's going on
faces = np.array([[0, 1, 2]])
average_vertex = vertices.sum(axis=0) / 3
vertices = laplacian_smooth(vertices, faces, 1)
assert (vertices == average_vertex).all()
def test_smoothing(volume):
ROUNDS = 3
vertices, normals, faces = marching_cubes.march(volume, 0)
smoothed_vertices, smoothed_normals, smoothed_faces = marching_cubes.march(volume, ROUNDS)
# Compare with our reference implementation of laplacian smoothing.
ref_smoothed_vertices = laplacian_smooth(vertices, faces, ROUNDS)
np.allclose(smoothed_vertices, ref_smoothed_vertices, rtol=0.001)
assert (faces == smoothed_faces).all(), \
"Smoothing should not affect face definitions."
assert not (normals == smoothed_normals).all(), \
"Normals should not be the same after smoothing."