def test_vector_alignment_find_rotation_random_vectors(self):
x = np.random.normal(size=(3,))
y = np.random.normal(size=(3,))
r = vector_alignment_find_rotation(x, y)
SurfingSurfaceTests._assert_rotation_maps_vector(r, x, y)
def test_vector_alignment_find_rotation_random_vectors(self):
x = np.random.normal(size=(3,))
y = np.random.normal(size=(3,))
r = vector_alignment_find_rotation(x, y)
SurfingSurfaceTests._assert_rotation_maps_vector(r, x, y)
def flat_surface2xy(surface, max_deformation):
'''Returns a tuple with x and y coordinates of a flat surface
Parameters
----------
surface: Surface
flat surface
max_deformation: float
maximum deformation to make a non-flat surface flat.
The normals of each face must have a dot product with the average
face normal that is not less than (1-max_deformation); otherwise
an exception is raised. The rationale for this option is that certain
surfaces may be almost flat, and those can be made flat without
problem; but surfaces that are not flat, such as inflated surfaces,
should not be flattable.
Returns
-------
x: np.ndarray
x coordinates
y: np.ndarray
y coordinates
Notes
-----
If the surface is not flat (any z coordinate is non-zero), an exception
is raised.
'''
s = surf.from_any(surface)
face_normals = s.face_normals
msk = np.all(np.logical_not(np.isnan(face_normals)), 1)
avg_face_normal = s.nanmean_face_normal
deformations = abs(
1 - abs(np.dot(avg_face_normal[np.newaxis], face_normals[msk].T)))
too_deformed = np.nonzero(deformations > max_deformation)[0]
if len(too_deformed) > 0:
raise ValueError('Surface is not sufficiently flat with '
'max_deformation=%.3f' % max_deformation)
# find rotation so that surface is more or less orthogonal to
# the unit vector (0,0,1)
v = s.vertices
z_axis = np.asarray([0, 0, 1.])
r = vector_alignment_find_rotation(avg_face_normal, z_axis)
# apply rotation
v_rotated = r.dot(v.T)
# discard z-coordinate
x = v_rotated[0]
y = v_rotated[1]
return x, y
def flat_surface2xy(surface, max_deformation):
'''Returns a tuple with x and y coordinates of a flat surface
Parameters
----------
surface: Surface
flat surface
max_deformation: float
maximum deformation to make a non-flat surface flat.
The normals of each face must have a dot product with the average
face normal that is not less than (1-max_deformation); otherwise
an exception is raised. The rationale for this option is that certain
surfaces may be almost flat, and those can be made flat without
problem; but surfaces that are not flat, such as inflated surfaces,
should not be flattable.
Returns
-------
x: np.ndarray
x coordinates
y: np.ndarray
y coordinates
Notes
-----
If the surface is not flat (any z coordinate is non-zero), an exception
is raised.
'''
s = surf.from_any(surface)
face_normals = s.face_normals
msk = np.all(np.logical_not(np.isnan(face_normals)), 1)
avg_face_normal = s.nanmean_face_normal
deformations = abs(
1 - abs(np.dot(avg_face_normal[np.newaxis], face_normals[msk].T)))
too_deformed = np.nonzero(deformations > max_deformation)[0]
if len(too_deformed) > 0:
raise ValueError('Surface is not sufficiently flat with '
'max_deformation=%.3f' % max_deformation)
# find rotation so that surface is more or less orthogonal to
# the unit vector (0,0,1)
v = s.vertices
z_axis = np.asarray([0, 0, 1.])
r = vector_alignment_find_rotation(avg_face_normal, z_axis)
# apply rotation
v_rotated = r.dot(v.T)
# discard z-coordinate
x = v_rotated[0]
y = v_rotated[1]
return x, y
def test_vector_alignment_find_rotation_canonical_vectors(self):
for i in xrange(3):
x = np.zeros((3,))
x[i] = 1
for j in xrange(3):
y = np.zeros((3,))
y[j] = 1
r = vector_alignment_find_rotation(x, y)
SurfingSurfaceTests._assert_rotation_maps_vector(r, x, y)
def test_vector_alignment_find_rotation_canonical_vectors(self):
for i in xrange(3):
x = np.zeros((3,))
x[i] = 1
for j in xrange(3):
y = np.zeros((3,))
y[j] = 1
r = vector_alignment_find_rotation(x, y)
SurfingSurfaceTests._assert_rotation_maps_vector(r, x, y)
