Face API Edge References

The face API identifies an edge from the faces around it instead of relying on the edge's position in a body's internal ordering. This makes references more stable when earlier modeling operations change the body's topology.

For most solid edges, the two adjacent faces uniquely identify the edge. Put those faces in sideFaces:

The faces in sideFaces run along the length of the edge. An operation can split an edge into multiple edges that still have the same side faces. To select one split, add an endFaces entry for a face touching the end of the intended edge:

Some solid-modeling topology can leave multiple edges with the same side and end faces. In that case, index selects one of the remaining matches using a zero-based index:

Prefer sideFaces alone when it is unambiguous. Add endFaces when an edge has been split, and use index only when the face information still leaves more than one match. When a Face API selection supplies an edge-reference object, keep the fields it provides rather than converting the selection to legacy edge helpers.

An edge-reference object does not have to identify exactly one edge. A broader reference can intentionally match multiple edges so that an operation applies to all of them. Add endFaces or index only when the operation should target a smaller subset of those matches.

Surface bodies do not always provide two side faces or useful end faces. Their edge references can therefore contain a single sideFaces entry and rely on index more often to choose a boundary edge.

The same edge-reference object can be used by operations such as fillet, chamfer, revolve, helix, and mirror3d where their parameter accepts an edge.

Sketch segments remain direct references, such as sketch001.line1. Edge reference objects are for edges on generated bodies, where adjacent face tags provide a stable description of the intended geometry.

Edges involving generated faces

Fillets and chamfers create new faces that can form part of edges used by later operations. Add tag to the edge-treatment operation to name its generated face, then use that tag in the later edge reference. The existing operation produces the face and should remain in the model; selecting one of its generated faces does not mean replacing the operation itself.

For example, this fillet targets the edge shared by the existing chamfer face and the extrusion's end cap: