Design Nomenclature / Form & Geometry
Profile
Also called generating curve, cross-section curve, moulding profile
The shape of a form's cross-section along its defining direction, or the curve that generates it — the section a sweep drags, the shape a moulding cutter is ground to. A profile is authored: it is an input to the form, which is what separates it from a section, taken out of a form that already exists.
In practice
Overlaps with 'silhouette' in casual speech and should not: a silhouette is a view of the whole thing, a profile is a curve you drew. Millwork, extrusion, and turning all take a profile as the deliverable.
Not to be confused with
- SectionThe figure produced by cutting a form with a plane and looking squarely at the cut face — only what the plane intersects, hatched, with nothing shown behind it. A section is taken from a form that exists. If it also draws what lies beyond the cut it is a sectional view. Wall thickness, ribs, and bosses are visible nowhere else.
- ContourA curve of constant height on a surface, read against a fixed direction — the level lines of a topographic map, the ribs of a stacked laser-cut model, the layers a slicer emits. A family of them describes the whole surface, and where they crowd, it is steep. Also used loosely for any line drawn following a form.
- SilhouetteThe outline a form presents from a given viewpoint — the boundary between surfaces facing the viewer and those facing away. It is view-dependent: the silhouette runs where the surface normal is perpendicular to the eye vector, and on a curved surface it is fixed to no edge in the mesh at all, which is why it slides as the camera moves.