Design Nomenclature / Form & Geometry
Contour
Also called level curve, isoline, contour line
- Form & Geometry
- Composition
- 2D & 3D
A 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.
In practice
Two live meanings. The cartographic one is precise and is what CAM, terrain, and slicing mean. The drawing one — a contour line as any line describing form — is what life drawing means, and it is not the same word doing the same work.
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.
- ProfileThe 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.