def test_spbox(self):
"""
Check volume change of the mesh which is deformed using
the SplineBox functions.
"""
from sfepy.discrete.fem import Mesh
from sfepy.mesh.splinebox import SplineBox
mesh = Mesh.from_file(data_dir + '/meshes/3d/cylinder.vtk')
conn = mesh.get_conn('3_4')
vol0 = tetravolume(conn, mesh.coors)
bbox = nm.array(mesh.get_bounding_box()).T
spbox = SplineBox(bbox, mesh.coors)
cpoints0 = spbox.get_control_points(init=True)
for ii in range(4):
for jj in range(4):
spbox.change_shape((0, ii, jj), [-0.02, 0, 0])
coors = spbox.evaluate()
vol1 = tetravolume(conn, coors)
mesh.coors[:] = coors
spbox.set_control_points(cpoints0)
coors = spbox.evaluate()
vol2 = tetravolume(conn, coors)
ok = True
actual_volumes = (vol0, vol1, vol2)
for ii in range(3):
relerr = abs(actual_volumes[ii] - expected_volumes[ii])\
/ expected_volumes[ii]
ok = ok and (relerr < 1e-6)
if not ok:
self.report('expected volumes:')
self.report(expected_volumes)
self.report('actual volumes:')
self.report(actual_volumes)
return ok
