In addition to 3D solids and surfaces, AutoCAD offers another type of 3D object, called mesh objects. Mesh objects are very similar to solids and surfaces. You can create surface meshes having the same shapes as surfaces, and you can create primitive mesh forms (boxes, pyramids, spheres, and so on) just like solid primitives, although mesh objects don't have the mass property present in the solid objects, but they can be modified in many other ways that cannot be done with regular 3D solid objects. The mesh object is divided into smaller volumes or cells, while the vertices, edges, and faces of these smaller volumes can be individually modified in many ways, as will be shown in this section of the chapter.