Two 3D Models Can Look Identical and Still Contain Different Knowledge
Geometry shows what the model looks like. Relationships, constraints and dependencies reveal what the model knows. Imagine two 3D models on a screen. They have the same dimensions. The same holes. The same edges. The same overall shape. Place one over the other and their visible geometry may match almost perfectly. It would be natural to conclude: These are the same model. But now change one dimension. The first model updates correctly. Related features move with it. Distances remain meaningful. Symmetry is preserved. Dependent geometry adapts. The second model begins to fall apart. A hole stays behind. An edge moves in the wrong direction. A feature loses its reference. The object still existed perfectly well before the change. So what was different? Not necessarily the visible geometry. The difference was in the knowledge encoded behind it . A 3D Model Is Not Just a Shape When beginners first work with CAD, the visible object naturally receives most of their attention. Does it look r...