def fix_missing_midside(cells, nodes, celltypes, offset, angles, nnum):
"""Adds missing midside nodes to cells.
ANSYS sometimes does not add midside nodes, and this is denoted in
the element array with a ``0``. When translated to VTK, this is
saved as a ``-1``. If this is not corrected, VTK will segfault.
This function creates missing midside nodes for the quadratic
elements.
"""
# Check for missing midside nodes
mask = cells == -1
nnodes = nodes.shape[0]
nextra = mask.sum()
cells[mask] = np.arange(nnodes, nnodes + nextra)
nodes_new = np.empty((nnodes + nextra, 3))
nodes_new[:nnodes] = nodes
nodes_new[nnodes:] = 0 # otherwise, segfault disaster
# Set new midside nodes directly between their edge nodes
temp_nodes = nodes_new.copy()
_relaxmidside.reset_midside(cells, celltypes, offset, temp_nodes)
# merge midside nodes
unique_nodes, idx_a, idx_b = unique_rows(temp_nodes[nnodes:])
# rewrite node numbers
cells[mask] = idx_b + nnodes
nextra = idx_a.shape[0] # extra unique nodes
nodes_new = nodes_new[:nnodes + nextra]
nodes_new[nnodes:] = unique_nodes
if angles is not None:
new_angles = np.empty((nnodes + nextra, 3))
new_angles[:nnodes] = angles
new_angles[nnodes:] = 0
else:
new_angles = None
# Add extra node numbers
nnum_new = np.empty(nnodes + nextra)
nnum_new[:nnodes] = nnum
nnum_new[nnodes:] = -1
return nodes_new, new_angles, nnum_new
def parse_vtk(self,
force_linear=False,
allowable_types=None,
null_unallowed=False):
"""Parses raw data into to VTK format.
Parameters
----------
force_linear : bool, optional
This parser creates quadratic elements if available. Set
this to True to always create linear elements. Defaults
to False.
allowable_types : list, optional
Allowable element types. Defaults to all valid element
types in ``from pyansys.elements.valid_types``
See help(pyansys.elements) for available element types.
null_unallowed : bool, optional
Elements types not matching element types will be stored
as empty (null) elements. Useful for debug or tracking
element numbers. Default False.
Returns
-------
grid : vtk.vtkUnstructuredGrid
VTK unstructured grid from archive file.
"""
if self.check_raw():
raise Exception('Invalid file or missing key data. ' +
'Cannot parse into unstructured grid')
# Convert to vtk style arrays
if allowable_types is None:
allowable_types = valid_types
else:
assert isinstance(allowable_types, list), \
'allowable_types must be a list'
for eletype in allowable_types:
if str(eletype) not in valid_types:
raise Exception('Element type "%s" ' % eletype +
'cannot be parsed in pyansys')
# construct keyoption array
keyopts = np.zeros((10000, 20), np.int16)
for keyopt_key in self.raw['keyopt']:
for index, value in self.raw['keyopt'][keyopt_key]:
keyopts[keyopt_key, index] = value
# parse raw output
parsed = _parser.parse(self.raw, force_linear, allowable_types,
null_unallowed, keyopts)
cells = parsed['cells']
offset = parsed['offset']
cell_type = parsed['cell_type']
numref = parsed['numref']
enum = parsed['enum']
# Check for missing midside nodes
if force_linear or np.all(cells != -1):
nodes = self.raw['nodes'][:, :3].copy()
nnum = self.raw['nnum']
angles = self.raw['nodes'][:, 3:]
else:
mask = cells == -1
nextra = mask.sum()
maxnum = numref.max() + 1
cells[mask] = np.arange(maxnum, maxnum + nextra)
nnodes = self.raw['nodes'].shape[0]
nodes = np.zeros((nnodes + nextra, 3))
nodes[:nnodes] = self.raw['nodes'][:, :3]
# Set new midside nodes directly between their edge nodes
temp_nodes = nodes.copy()
_relaxmidside.reset_midside(cells, cell_type, offset, temp_nodes)
nodes[nnodes:] = temp_nodes[nnodes:]
# merge nodes
new_nodes = temp_nodes[nnodes:]
unique_nodes, idxA, idxB = unique_rows(new_nodes)
# rewrite node numbers
cells[mask] = idxB + maxnum
nextra = idxA.shape[0]
nodes = np.empty((nnodes + nextra, 3))
nodes[:nnodes] = self.raw['nodes'][:, :3]
nodes[nnodes:] = unique_nodes
angles = np.empty((nnodes + nextra, 3))
angles[:nnodes] = self.raw['nodes'][:, 3:]
angles[nnodes:] = 0
# Add extra node numbers
nnum = np.hstack(
(self.raw['nnum'], np.ones(nextra, np.int32) * -1))
# Create unstructured grid
grid = pv.UnstructuredGrid(offset, cells, cell_type, nodes)
# Store original ANSYS element and cell information
grid.point_arrays['ansys_node_num'] = nnum
grid.cell_arrays['ansys_elem_num'] = enum
grid.cell_arrays['ansys_elem_type_num'] = parsed['etype']
grid.cell_arrays['ansys_real_constant'] = parsed['rcon']
grid.cell_arrays['ansys_material_type'] = parsed['mtype']
grid.cell_arrays['ansys_etype'] = parsed['ansys_etype']
# Add element components to unstructured grid
for comp in self.raw['elem_comps']:
mask = np.in1d(enum,
self.raw['elem_comps'][comp],
assume_unique=True)
grid.cell_arrays[comp.strip()] = mask
# Add node components to unstructured grid
for comp in self.raw['node_comps']:
mask = np.in1d(nnum,
self.raw['node_comps'][comp],
assume_unique=True)
grid.point_arrays[comp.strip()] = mask
# Add tracker for original node numbering
ind = np.arange(grid.number_of_points)
grid.point_arrays['origid'] = ind
grid.point_arrays['VTKorigID'] = ind
# store node angles
grid.point_arrays['angles'] = angles
self.grid = grid
return grid
