"""
defines:
- stl = nastran_to_stl_filename(bdf_filename, stl_filename, is_binary=False,
log=None)
- stl = nastran_to_stl(bdf_filename, stl_filename, is_binary=False,
log=None, stop_on_failure=False)
"""
import numpy as np
from pyNastran.bdf.bdf import read_bdf
from pyNastran.converters.stl.stl import STL
[docs]
def nastran_to_stl_filename(bdf_filename, stl_filename, is_binary=False, log=None):
"""Converts a Nastran model to an STL"""
return nastran_to_stl(bdf_filename, stl_filename, is_binary=is_binary)
[docs]
def nastran_to_stl(bdf_filename, stl_filename, is_binary=False, log=None, stop_on_failure=False):
"""
Converts a Nastran model to an STL
Parameters
----------
bdf_filename : varies
str : the path to a BDF input file
BDF() : a BDF() model object
stl_filename : str
the output STL path
is_binary : bool; default=False
should the output file be binary
log : Logger()
a Python logging object
stop_on_failure : bool; default=False
should the code stop if an error is encountered
"""
if isinstance(bdf_filename, str):
model = read_bdf(bdf_filename, log=log)
else:
model = bdf_filename
#log.info('card_count = %s' % model.card_count)
nnodes = len(model.nodes)
nodes = np.zeros((nnodes, 3), dtype='float64')
elements = []
i = 0
nodeid_to_i_map = {}
offset = False
if offset:
nid = list(model.nodes.keys())[0]
xyz0 = model.nodes[nid].get_position()
else:
xyz0 = np.zeros(3, dtype='float64')
for node_id, node in sorted(model.nodes.items()):
xyz = node.get_position()
nodes[i, :] = xyz - xyz0
nodeid_to_i_map[node_id] = i
i += 1
assert len(model.nodes) == i, 'model.nodes=%s i=%s' % (len(model.nodes), i)
for unused_eid, element in sorted(model.elements.items()):
if element.type in ['CQUADR']:
continue
elif element.type in ['CBAR', 'CBEAM', 'CONM2', 'RBE2', 'RBE3',
'CBUSH', 'CBUSH1D', 'CBUSH2D',
'CONROD', 'CROD',
'CELAS1', 'CELAS2', 'CELAS3', 'CELAS4',
'CDAMP1', 'CDAMP2', 'CDAMP3', 'CDAMP4',]:
continue
elif element.type in ['CQUAD4']:
n1, n2, n3, n4 = element.node_ids
i1, i2, i3, i4 = (nodeid_to_i_map[n1], nodeid_to_i_map[n2],
nodeid_to_i_map[n3], nodeid_to_i_map[n4])
elements.append([i1, i2, i3])
elements.append([i3, i4, i1])
elif element.type in ['CTRIA3', 'CTRIAR']:
nids = element.node_ids
unids = np.unique(nids)
if len(unids) == 2:
continue
n1, n2, n3 = nids
i1, i2, i3 = nodeid_to_i_map[n1], nodeid_to_i_map[n2], nodeid_to_i_map[n3]
elements.append([i1, i2, i3])
else:
model.log.warning('skipping %s' % element.type)
elements = np.array(elements, dtype='int32')
stl = STL(log=model.log)
stl.nodes = nodes
#stl.nodes -= nodes[0, :]
stl.elements = elements
stl.write_stl(stl_filename, is_binary=is_binary, stop_on_failure=stop_on_failure)
return stl