Polymesh.virtual_entities() returns incorrect Face3d

[mozman]

^{Originally posted by chibai December 17, 2021}
I'm trying to extract the basic element from a polyline(polyface)
But the vertices of the entity make me crazy
test.zip

from ezdxf import recover
from ezdxf.addons.drawing import matplotlib
# Exception handling left out for compactness:
doc, auditor = recover.readfile('test.dxf')
if not auditor.has_errors:
    matplotlib.qsave(doc.modelspace(), 'test.png')
for entity in doc.modelspace():
    if entity.dxf.handle == 'F6AC':
        e = list(entity.virtual_entities())[0]
        print(e.wcs_vertices())

skipped entity 3DFACE(#EC29). Reason: "invisible"
skipped entity 3DFACE(#EC2A). Reason: "invisible"
skipped entity 3DFACE(#EC2B). Reason: "invisible"
[Vec3(59416.31455091119, 21790.91531877725, 0.0), Vec3(59361.25307228302, 21813.84830555742, 0.0), Vec3(59380.16605928067, 21806.95449032696, 0.0), Vec3(0.0, 0.0, 0.0)]

The Vec3(0, 0, 0) if definitely not belong to the entity!

[mozman]

Alternative way to get faces and vertices from PolyFaceMesh without creating virtual entities:

docs: https://ezdxf.mozman.at/docs/render/mesh.html

from ezdxf.render import MeshBuilder

...

# sadly the PolyFaceMesh entity is a variant of the POLYLINE entity, like the PolygonMesh entity
for entity in doc.modelspace().query("POLYLINE"):  
    if entity.is_poly_face_mesh:
        print(f"PolyFaceMesh: {str(entity)}")
        builder = MeshBuilder.from_polyface(entity)
        # all vertices used in the mesh independently from the face structure
        print(f"count of vertices: {len(builder.vertices)}")
        # get all mesh faces as list of Vec3() objects in WCS coordinates
        faces = list(builder.faces_as_vertices())
        print(f"count of faces: {len(faces)}")
        for face in faces:
            print(face)

[chibai]

Thank you！