While editing a Morph, its shape may be transformed such that a single face is intersected by other parts of the Morph. At this point, the new (self-)intersection is not yet delimited by any edges.
If you henceforth want to treat such intersecting faces separately, use the Design > Modify Morph > Intersect Morph Faces command.
This command works on a single selected Morph only.
Relevant topics
Combine Morph Faces for Smooth Editing Effect: Use “Soft” Edges
Morph editing often involves selecting and editing a sub-element (edge, node or face), which in turn affects the connecting faces of the Morph.
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Example 8: Generate Expanded ID for Openings
Automatically generate an expanded ID for all Doors and Windows that includes:
•Element ID
•Home Story Number
•Opening ...
Intersect Two Elements
You can intersect two selected elements with each other by having them meet at their endpoints’ nearest point.
This command works on ...