Scotty3D stores and manipulates meshes using a halfedge mesh structure – a local connectivity description which allows for fast local topology changes and has clear storage locations for data associated with vertices, edges, faces, and face-corners (/edge-sides).

Local Operations

Flip Edge/ Split Edge/ Collapse Edge/ Extrude Face/ Dissolve Vertex/ Collapse Face

The most challenging operation is Collapse Edge, with bugs often going unnoticed until the global operation is executed and the issue becomes visible in the GUI.

Global Operations

Triangulation/ Linear Subdivision Positions/ Catmull-Clark Subdivision Positions / Isotropic Remeshing

Final model

The online resource provides a penguin model that can be modified using global operations.

An unresolved bug caused by the Collapse Edge operation makes the edge of my tank appear uneven.