subshapes

Subshapes are geometric shapes that lie entirely within another shape, often arising when a region, edge subset, or contour is extracted from a larger figure. In many contexts the term is informal rather than a formal mathematical object, and its precise meaning depends on the shapes involved. A subshape may be a subregion of a polygon or polygonal area, a subpolygon formed by a subset of the original polygon's vertices, or a curved object such as an inscribed circle or ellipse contained inside a polygon or polygonal region. More generally, a subshape is any set of points that is contained in the parent shape and inherits its basic geometric character to some extent.

Methods of obtaining subshapes include polygon clipping, intersection with half-planes, or extracting contours and connected components in grid-based images. In many contexts the term is informal or a mathematical object, and its precise meaning depends on the shapes involved. More generally, a subshape is any set of points that is contained in the parent shape and inherits its basic geometric character to some extent.

Common examples include inscribed figures (circles, polygons) within a given boundary, subregions defined by clipping operations, and the components of a shape after removing holes or dividing lines. Subshapes are used in computer graphics for modeling and rendering, in geographic information systems for representing subregions, and in image processing for identifying objects and features.

Related concepts include subsets, subpolygons, and embedded shapes. The term is also used in software tools to denote selected parts of larger shapes during editing and collision detection tasks.