rectiligne

Rectiligne is an adjective meaning straight or lying along a straight line. The term is used mainly in French as rectiligne; in English the equivalent is rectilinear. It derives from Latin rectus (straight) and linea (line).

In geometry, a rectiligne element is a straight-line segment, and a rectilinear figure is composed entirely of straight-line segments. A path is rectiligne if its entire trajectory lies on a single straight line.

In physics, rectilinear motion denotes movement along a straight line. It can be uniform (constant speed) or non-uniform; in either case, the motion has no curvature and the direction remains fixed unless speed changes.

In computer graphics and imaging, rectilinear projection preserves straight lines in the scene, producing a natural perspective for flat, non-curved camera lenses; by contrast, some wide-angle projections introduce non-rectilinear distortions.

Rectiligne concepts also appear in architecture and design, describing forms dominated by straight edges and right angles, as opposed to curved geometries.

See also: rectilinearity, straight line, rectilinear projection.