Polygonmeshes

Polygonmeshes are a widely used representation of three-dimensional surfaces in computer graphics and related fields. They describe a surface as a collection of polygonal faces connected by edges and vertices, providing a discrete approximation of a smooth or complex shape.

Most meshes are composed of vertices (points in 3D space), edges (line segments between vertices), and faces (polygons defined by an ordered list of vertex indices). Triangular meshes, where every face has three vertices, are the most common due to robustness and efficient GPU rasterization; quadrilateral meshes are also used, especially in modeling workflows and subdivision surfaces.

Meshes store geometric information (vertex positions) and topological information (which vertices form which faces). Per-vertex normals, texture coordinates, and other attributes are often included to support shading and rendering. Topology can be manifold or non-manifold; watertight meshes have closed surfaces without gaps, while non-manifold meshes may contain edges shared by more than two faces or boundary edges.

Common operations on polygonmeshes include subdivision (refining a mesh to produce smoother surfaces), decimation or simplification (reducing polygon count), smoothing, remeshing, and repair (opening holes or fixing inconsistencies).

During rendering, meshes are processed by graphics pipelines that shade vertices or fragments, often using flat, Gouraud, or Phong shading, with texture mapping via UV coordinates. Meshes can be stored in various formats and converted between representations for workflows and rendering engines.

Common data formats include OBJ, STL, PLY, OFF, and glTF; specialized formats and libraries support advanced features such as skinning, morph targets, and level-of-detail. Polygonmeshes are used in 3D modeling, animation, simulation, gaming, CAD, and 3D printing, where their simplicity and versatility make them a standard choice.