Surfacesouter

Surfacesouter is a term used in geometry and computer graphics to denote the outer surface of a closed three-dimensional object. It refers to the boundary between the object's interior and its exterior, and is typically equipped with an outward-pointing normal vector. In formal topology, if M is a compact solid in three-dimensional space with boundary, then the boundary ∂M is the outer surface of M.

For objects with holes or handles, the outer surface may have multiple components, each with a consistent outward normal.

Computationally, surfacesouter often refers to the processed representation of the outer boundary, extracted from volumetric data or point clouds. Common methods to recover the outer surface include computing the convex hull, alpha shapes, Poisson surface reconstruction, and marching cubes. Challenges include noise, holes, non-manifold edges, and determining correct orientation.

Outer surfaces are stored as polygonal meshes or triangulated surfaces, with vertex coordinates and face indices; normals can be computed or stored. Sometimes parametric or implicit representations are used to describe the same outer boundary, depending on the application and data format.

See also: boundary, outer boundary, convex hull, surface reconstruction, manifold.