def extrude(self, displaced):
"""
radially extrude a surface mesh into a solid
given a bounded surface, return a closed solid
create extra options; rather than plain radial extrude,
we can also do swepth sphere extrude; better for casting
"""
points = len(self.vertices)
#construct edge information
edges = self.edges()
boundary = npi.multiplicity(self.order_edges(edges)) == 1
eb = edges[boundary]
if len(eb) == 0: raise Exception('Surface to be extruded is closed, thus does not have a boundary')
#construct closed solid
boundary_tris = np.concatenate((
np.concatenate((eb[:,::-1], eb[:,0:1]+points),axis=1),
np.concatenate((eb[:,::+1]+points, eb[:,1:2]),axis=1)
))
copy_tris = self.faces[:, ::-1] + points
solid_points = np.concatenate((self.vertices, displaced))
solid_tris = np.concatenate((self.faces, copy_tris, boundary_tris))
mesh = Mesh(solid_points, solid_tris)
if mesh.volume() < 0:
mesh.faces = mesh.faces[:, ::-1]
return mesh
def boundary(self):
edges = self.edges()
return edges[npi.multiplicity(self.order_edges(edges)) == 1]
def boundary(self):
edges = self.edges()
return edges[npi.multiplicity(self.order_edges(edges)) == 1]
