created by the modeling environment. Common primitives include: Cubes Pyramids Cylinders 2D primitives, such as squares, triangles, and disks Specialized or esoteric primitives, such as the Utah Teapot or Suzanne, Blender's monkey mascot. Spheres - Spheres are commonly represented in one of two ways: Icospheres are icosahedrons which possess a sufficient number of triangles to resemble a sphere. UV spheres are composed of quads, and resemble the grid seen on some globes - quads are larger near the "equator" of the sphere and smaller near the "poles," eventually terminating in a single vertex. Finally, some specialized methods of constructing high or low detail meshes exist. Sketch based modeling is a user-friendly interface for constructing low-detail models quickly, while 3D scanners can be used to create high detail meshes based on existing real-world objects in an almost automatic way. These devices are very expensive, and are generally only used by researchers and industry professionals but can generate high accuracy sub-millimetric digital representations. Operations There are a very large number of operations which may be performed on polygonal meshes. Some of these roughly correspond to real-world manipulations of 3D objects, while others do not. Polygonal mesh operations include: Creations - Create new geometry from some other mathematical object Loft - Generate a mesh by creating a shape along two or more profile curves Extrude - Creates a surface by sweeping a profile curve or polygon surface along a straight or linear line Revolve - Generate a mesh by revolving (rotating) a shape around an axis Marching cubes - Algorithm to construct a mesh from an implicit function Binary Creations - Create a new mesh from a binary operation of two other meshes Add - Boolean addition of two or more meshes Subtract - Boolean subtraction of two or more meshes Intersect - Boolean intersection Union - Boolean union of two or more meshes Attach - Attach one mesh to another (removing the interior surfaces) Chamfer - Create a beveled surface which smoothly connects two surfaces Deformations - Move only the vertices of a mesh Deform - Systematically move vertices (according to certain functions or rules) Weighted Deform - Move vertices based on localized weights per vertex Morph - Move vertices smoothly between a source and target mesh Bend - Move vertices to "bend" the object Twist - Move vertices to "twist" the object Manipulations - Modify the geometry of the mesh, but