def write_mesh(geo_filename, preview=False):
# Initialize the gmsh api.
gmsh.initialize()
# Save the mesh with v2 to use it with dolfin-converter application.
gmsh.option.setNumber("Mesh.MshFileVersion", 2.)
# Re-open the file.
gmsh.open(geo_filename)
# Generate the 2D mesh.
gmsh.model.mesh.generate(2) # 2 indicating 2 dimensions.
msh_filename = geo_filename.split('.geo')[0] + '.msh'
gmsh.write(msh_filename)
# Finalize the gmsh processes.
gmsh.finalize()
if preview:
open_gmsh(msh_filename)
return msh_filename
def generate__semiCircleMesh( lc1=0.01, lc2=0.05, lc3=0.1, radius=1.0, origin=[0.0,0.0], \
th1=-90.0,th2=+90.0, zoffset=0.0, side="+" ):
# ------------------------------------------------- #
# --- [1] initialization of the gmsh --- #
# ------------------------------------------------- #
gmsh.initialize()
gmsh.option.setNumber( "General.Terminal", 1 )
gmsh.model.add( "model" )
# ------------------------------------------------- #
# --- [2] initialize settings --- #
# ------------------------------------------------- #
ptsDim , lineDim , surfDim , voluDim = 0, 1, 2, 3
pts , line , surf , volu = {}, {}, {}, {}
ptsPhys, linePhys, surfPhys, voluPhys = {}, {}, {}, {}
x_, y_, z_, lc_, tag_ = 0, 1, 2, 3, 4
# ------------------------------------------------- #
# --- [3] Modeling --- #
# ------------------------------------------------- #
initNum = 1
x_, y_ = 0, 1
pth1, pth2 = th1/180.0*np.pi, th2/180.0*np.pi
xp1 = [ origin[x_]+radius*np.cos(pth1), origin[y_]+radius*np.sin(pth1) ]
xp2 = [ origin[x_]+radius*np.cos(pth2), origin[y_]+radius*np.sin(pth2) ]
pts["OP"] = [ origin[x_], origin[y_], zoffset, lc2, initNum ]
pts["P1"] = [ xp1[x_], xp1[y_], zoffset, lc1, initNum ]
pts["P2"] = [ xp2[x_], xp2[y_], zoffset, lc3, initNum ]
ang = 0.5*(pth2-pth1) + pth1
if ( ( th2-th1 == 180.0 ) & ( side=="+" ) ):
xp3 = [ origin[x_] + radius*np.cos( ang ), origin[y_] + radius*np.sin( ang ) ]
elif ( ( th2-th1 == 180.0 ) & ( side=="-" ) ):
xp3 = [ origin[x_] - radius*np.cos( ang ), origin[y_] - radius*np.sin( ang ) ]
else:
xp3 = [ origin[x_] + radius*np.cos( ang ), origin[y_] + radius*np.sin( ang ) ]
pts["P3"] = [ xp3[x_], xp3[y_], zoffset, lc2, initNum ]
for key in list( pts.keys() ):
pt = pts[key]
( pts[key] )[4] = gmsh.model.occ.addPoint( pt[0], pt[1], pt[2], meshSize=pt[3] )
line["arc1"] = gmsh.model.occ.addCircleArc( pts["P1"][4], pts["OP"][4], pts["P3"][4] )
line["arc2"] = gmsh.model.occ.addCircleArc( pts["P3"][4], pts["OP"][4], pts["P2"][4] )
line["diameter1"] = gmsh.model.occ.addLine( pts["OP"][4], pts["P1"][4] )
line["diameter2"] = gmsh.model.occ.addLine( pts["P2"][4], pts["OP"][4] )
LineLoop = [ + line["diameter1"], + line["arc1"], \
+ line["arc2"] , + line["diameter2"] ]
LineLoopGroup = gmsh.model.occ.addCurveLoop( LineLoop )
surf["sector"] = gmsh.model.occ.addPlaneSurface( [ LineLoopGroup ] )
# ------------------------------------------------- #
# --- [4] Physical Grouping --- #
# ------------------------------------------------- #
gmsh.model.occ.synchronize()
surfPhys["semicircle"] = gmsh.model.addPhysicalGroup( surfDim, [ surf["sector"] ], tag=201 )
# ------------------------------------------------- #
# --- [5] post process --- #
# ------------------------------------------------- #
gmsh.model.occ.synchronize()
gmsh.model.mesh.generate(2)
gmsh.write( "model.geo_unrolled" )
gmsh.write( "model.msh" )
gmsh.finalize()
volu["cylinder"] = ret[1][1]
# ------------------------------------------------- #
# --- [4] PostProcess --- #
# ------------------------------------------------- #
ret = {"pts": pts, "line": line, "surf": surf, "volu": volu}
return (ret)
# ======================================== #
# === 実行部 === #
# ======================================== #
if (__name__ == "__main__"):
gmsh.initialize()
gmsh.option.setNumber("General.Terminal", 1)
gmsh.model.add("example")
lc = 0.10
xc = [0.0, 0.0, 0.0]
radius = 1.0
delta = [0.0, 0.0, 1.0]
generate__cylinder( lc=lc, xc=xc, radius=radius, \
defineVolu=True, extrude_delta=delta )
gmsh.model.occ.synchronize()
gmsh.model.mesh.generate(3)
gmsh.write("example.geo_unrolled")
gmsh.write("example.msh")
gmsh.finalize()
def execute(self, context):
scene = context.scene
try:
import gmsh_api.gmsh as gmsh
if scene.blendmsh.initialized:
filename = bpy.context.active_object.name
active_object = bpy.context.active_object
physical_group_faces = OrderedDict()
bpy.ops.object.mode_set(mode='OBJECT')
for _face in bpy.context.active_object.data.polygons:
if 'GROUP' in active_object.data.materials[
_face.material_index].name_full:
group_id = str(active_object.data.materials[
_face.material_index].name_full)
# GMSH INDEX STARTS FROM 1, HENCE '_face.index + 1'
if group_id not in physical_group_faces.keys():
physical_group_faces[group_id] = set(
[_face.index + 1])
else:
physical_group_faces[group_id].add(_face.index + 1)
data = self.get_raw_data(
os.path.join(scene.blendmsh.workspace_path,
filename + '.stl'))
points = OrderedDict()
edges = OrderedDict()
triangles = OrderedDict()
curve_loop = OrderedDict()
geo_points = OrderedDict()
geo_edges = OrderedDict()
i = 1
for _surface in data:
for _vertex in _surface:
if _vertex not in points.keys():
points[_vertex] = i
geo_points[i] = _vertex
i += 1
for i, _data in enumerate(data):
triangles[i + 1] = [
points[_data[0]], points[_data[1]], points[_data[2]]
]
i = 1
for _triangle in triangles.values():
for _edge in self.get_edge_indices(_triangle):
if _edge not in edges.keys(
) and _edge[::-1] not in edges.keys():
edges[_edge] = i
geo_edges[i] = _edge
i += 1
for _triangle_id in triangles.keys():
curve_loop[_triangle_id] = []
for connection in self.get_curve_loop(
triangles[_triangle_id]):
if connection in edges.keys():
curve_loop[_triangle_id].append(edges[connection])
elif connection[::-1] in edges.keys():
curve_loop[_triangle_id].append(
-1 * edges[connection[::-1]])
all_physical_group_faces = set()
for _face_lists in physical_group_faces.values():
for _face_id in _face_lists:
all_physical_group_faces.add(_face_id)
gmsh.initialize()
gmsh.option.setNumber('General.Terminal', 1)
lc = scene.blendmsh.cl_max
geo = gmsh.model.geo
for _point in points.keys():
geo.addPoint(_point[0], _point[1], _point[2], lc,
points[_point])
for _edge in edges.keys():
geo.addLine(_edge[0], _edge[1], edges[_edge])
for _curve_id in curve_loop.keys():
geo.addCurveLoop([
curve_loop[_curve_id][0], curve_loop[_curve_id][1],
curve_loop[_curve_id][2]
], _curve_id)
surf_temp = geo.addPlaneSurface([_curve_id], _curve_id)
if _curve_id in all_physical_group_faces:
gmsh.model.addPhysicalGroup(2, [surf_temp], _curve_id)
sl = geo.addSurfaceLoop(list(curve_loop.keys()))
_ = geo.addVolume([sl])
gmsh.model.geo.synchronize()
gmsh.option.setNumber("Mesh.Algorithm",
int(scene.blendmsh.algorithm))
gmsh.option.setNumber("Mesh.ElementOrder",
int(scene.blendmsh.element_order))
gmsh.option.setNumber("Mesh.Optimize", 1)
gmsh.option.setNumber("Mesh.QualityType", 2)
gmsh.option.setNumber("Mesh.SaveAll", 1)
gmsh.model.mesh.generate(int(scene.blendmsh.mesh_dimension))
gmsh.write(
os.path.join(scene.blendmsh.workspace_path,
filename + scene.blendmsh.output_file_format))
gmsh.finalize()
self.report({'INFO'}, '{} file written to {}'.format(
filename + scene.blendmsh.output_file_format,
scene.blendmsh.workspace_path))
return {'FINISHED'}
else:
self.report({
'ERROR'
}, 'Kindly initialize geometry before defining physical groups.'
)
return {'CANCELLED'}
except ModuleNotFoundError:
self.report(
{'ERROR'},
'Couldnot import Gmsh module, Kindly re-install it manually.')
return {'CANCELLED'}
def generate_mesh(fractures_data,
max_el_size,
file_name,
verbose=0,
shape="circle"):
r""" Create mesh and write it to a file.
Parameters
----------
fractures_data : list of FractureData
Array of objects defining fractures.
max_el_size : double
Maximal size of mesh element.
file_name : str
File name to write mesh into.
verbose : {0, 1}
If set to 1, messages during mesh generation will be printed.
"""
model = gmsh.model
factory = model.occ
gmsh.initialize()
gmsh.option.setNumber("General.Terminal", verbose)
model.add("test_api")
# set options
gmsh.option.setNumber("Geometry.Tolerance", 0)
gmsh.option.setNumber("Geometry.ToleranceBoolean", 0)
gmsh.option.setNumber("Geometry.MatchMeshTolerance", 0)
gmsh.option.setNumber("Mesh.ToleranceInitialDelaunay", 1e-12)
gmsh.option.setNumber("Mesh.CharacteristicLengthFromPoints", 1)
gmsh.option.setNumber("Mesh.CharacteristicLengthFromCurvature", 0)
gmsh.option.setNumber("Mesh.CharacteristicLengthExtendFromBoundary", 0)
# gmsh.option.setNumber("Mesh.CharacteristicLengthMin", max_el_size*0.01)
# gmsh.option.setNumber("Mesh.CharacteristicLengthMax", max_el_size)
# gmsh.option.setNumber("Mesh.MinimumCurvePoints", 5)
# Generate fractures
if shape == "circle":
fractures = generate_disks(factory, fractures_data)
# elif shape == "rectangle":
# fractures = generate_rectangles(factory, fractures_data)
# elif shape == "ellipse":
# fractures = generate_ellipses(factory, fractures_data)
# set physical id and name of fractures
fractures_phys_id = model.addPhysicalGroup(2, [x[1] for x in fractures],
-1)
model.setPhysicalName(2, fractures_phys_id, "fractures")
# define 3d volume and embed fractures into it
box = factory.addBox(0, 0, 0, 1, 1, 1)
factory.synchronize()
# Embed the model entities of dimension 'dim', and tags 'tag' in the other model entity which is given by
# dimension (3) and tag (box)
model.mesh.embed(2, [tag for dim, tag in fractures], 3, box)
# define physical id of volume and its boundaries
box_phys_id = model.addPhysicalGroup(3, [box], -1)
model.setPhysicalName(3, box_phys_id, "box")
# box_bdry = model.getBoundary([(3,box)], True)
# box_bdry_left_phys_id = model.addPhysicalGroup(2, [box_bdry[0][1]], -1)
# box_bdry_right_phys_id = model.addPhysicalGroup(2, [box_bdry[1][1]], -1)
# model.setPhysicalName(2, box_bdry_left_phys_id, ".left")
# model.setPhysicalName(2, box_bdry_right_phys_id, ".right")
# Define fields for mesh refinement
# Compute the distance from curves, each curve is replaced by NNodesByEdge equidistant nodes
# and the distance from those nodes is computed.
model.mesh.field.add("Distance", 1)
model.mesh.field.setNumber(1, "NNodesByEdge", 100)
frac_bdry = model.getBoundary(fractures, False, False, False)
# Set the numerical list option "EdgesList" to list of "frac_bdry" tags for field tag 1.
model.mesh.field.setNumbers(1, "EdgesList",
[tag for dm, tag in frac_bdry if dm == 1])
# Threshold
# F = LCMin if Field[IField] <= DistMin,
# F = LCMax if Field[IField] >= DistMax,
# F = interpolation between LcMin and LcMax if DistMin < Field[IField] < DistMax
model.mesh.field.add("Threshold", 2)
# Index of the field to evaluate (in this case 1 is "Distance")
model.mesh.field.setNumber(2, "IField", 1)
# Element size inside DistMin
model.mesh.field.setNumber(2, "LcMin", max_el_size * 0.03)
# Element size outside DistMax
model.mesh.field.setNumber(2, "LcMax", max_el_size)
# Distance from entity up to which element size will be LcMin, it should depend on particular model
model.mesh.field.setNumber(2, "DistMin", 0.001)
# Distance from entity after which element size will be LcMax, it should depend on particular model
model.mesh.field.setNumber(2, "DistMax", 0.5)
# Set threshold as the background mesh size field.
model.mesh.field.setAsBackgroundMesh(2)
# generate mesh, write to file and output number of entities that produced error
factory.synchronize()
gmsh.write(file_name + '.brep')
model.mesh.generate(3)
bad_entities = model.mesh.getLastEntityError()
gmsh.write(file_name)
gmsh.finalize()
return len(bad_entities)
