Mesh objects do not have the mass and volume properties of 3D solids. However, they
do offer unique capabilities that enable you to design less angular, more rounded
models. Mesh objects are easier to mold and reshape than their solid and surface counterparts.

About Mesh Faces

Mesh objects are composed of faces and facets.

Faces are non-overlapping units that—along with their edges and vertices—form the
basic editable units of a mesh object. When you move, rotate, and scale individual
mesh faces, surrounding faces are stretched and deformed in order to avoid introducing
gaps. When gaps occur, you can often close them by smoothing the object or refining
individual faces.

About Mesh Facets

Mesh faces have underlying structures, known as facets. The density of the facet
grid corresponds to the smoothness of the mesh. As the smoothness level is increased,
the density of the underlying facet grid also increases. When you want to confine
detailed mesh editing to a smaller area, you can convert facets to editable faces
by using refinement.

Unlike faces, facets cannot be individually modified. However, you can make them more
visible by modifying the VSLIGHTINGQUALITY system variable.

About Mesh Modeling

You can work with mesh objects in the following ways:

• Add smoothness. Increase or decrease smoothness levels to round the overall shape of the model. The
  underlying density of the mesh facet grid increases as the mesh object smoothness
  level increases (MESHSMOOTHMORE, MESHSMOOTHLESS).
• Refine the object to reset the baseline smoothness level. Refine a mesh object to convert the underlying facet grid to editable faces. Refinement
  also resets the lowest level of smoothness that can be applied to the object (MESHREFINE).

• Refine a face. Restrict the refinement to a specific mesh face. This method avoids resetting the
  smoothness baseline.
• Crease an edge. Remove the smoothness from specified edges. You can also remove an existing crease
  (MESHCREASE).
• Split or merge faces. Divide an existing face into separate components along a specified path. Merge two
  or more faces to create a single face (MESHSPLIT, MESHMERGE).
• Collapse vertices. Alter the mesh model by collapsing the vertices of adjacent faces to a single point
  (MESHCOLLAPSE).
• Spin edges. Spin the shared edge of adjacent triangular faces to alter the shapes and orientation
  of the faces (MESHSPIN).
• Extrude a face. Extend a specified face by extruding it into 3D space. Unlike 3D solid extrusion,
  a mesh extrusion does not create a separate object (MESHEXTRUDE).
• Repair holes. Close a gap between faces by selecting the surrounding edges. Holes in mesh objects
  can prevent you from converting a mesh object to a solid object (MESHCAP).

Use Grip Editing with Mesh

You can manipulate the entire mesh model or individual subobjects using the following
methods:

• Subobject selection and editing. Select faces, edges, and vertices the same way you select 3D solid subobjects. Press
  and hold Ctrl while selecting a subobject. The subobject highlighting indicates what
  is selected. Press and hold Shift and click again to remove the selection from a subobject.
  By turning on the Subobject Selection Filter, you can restrict selection to a specific
  subobject, which you can select without pressing and holding Ctrl.
• Gizmo editing. When you select a mesh object or subobject, the 3D Move, Rotate, or Scale gizmo
  is displayed automatically. (You can set which gizmo is displayed by default.) Use
  these gizmos to modify the selection uniformly, or along a specified plane or axis.

Because dense meshes can be difficult to work with, you can change settings to improve
the display and behavior of grips.

• Set the subobject selection filter: Set the DEFAULTGIZMO system variable or use the shortcut menu to select only faces,
  edges, or vertices.
• Set whether a grip is active immediately when you select the subobject: Set the GRIPSUBOBJMODE system variable.