Mesh tessellation provides enhanced capabilities
for modeling object shapes in a more detailed way.
Starting with AutoCAD 2010,
the default mesh object type can be smoothed, creased, split, and
refined. Although you can continue to create the legacy polyface
and polygon mesh types, you can obtain more predictable results
by converting to the newer mesh object type.
Show Me: Mesh Modeling Overview
Click the Play arrow
to start the animation.
Methods for Creating Mesh
You can create mesh objects
using the following methods:
Create mesh primitives. Create
standard shapes, such as boxes, cones, cylinders, pyramids, spheres,
wedges, and tori (MESH).
Create mesh from other
objects. Create ruled, tabulated, revolved, or edge-defined
mesh objects, whose boundaries are interpolated from other objects
or points (RULESURF, TABSURF, REVSURF, EDGESURF).
Convert from other object
types. Convert existing solid or surface models, including
composite models, to mesh objects (MESHSMOOTH).
You can also convert
the legacy style of mesh to the new mesh object type.
Create custom meshes (legacy). Use 3DMESH to create polygon
meshes, usually scripted with AutoLISP routines, to create open-ended
mesh. Use PFACE to create mesh
with multiple vertices defined by coordinates that you specify.
Although you can continue to create legacy polygonal and polyface
meshes, it is recommended that you convert to the enhanced mesh
object type to obtain enhanced editing capabilities.
About Tessellation
Tessellation
is a collection of planar shapes that tile a mesh object. The tessellation
divisions, visible in unselected mesh objects, mark the edges of
the editable mesh faces. (To see these divisions in the 3D Hidden
or Conceptual visual styles, VSEDGES must be set to
1.)
When you smooth and refine
mesh objects, you increase the density of the tessellation (the
number of subdivisions).
Smoothing. Increases
how closely the mesh surface adheres to a rounded form. You can
increase mesh smoothness levels for selected objects in increments
or by changing the smoothness level in the Properties palette. Smoothness
level 0 (zero) applies the lowest level of smoothing to a mesh object.
Smoothness level 4 applies a high degree of smoothness.
Refinement. Quadruples
the number of subdivisions in a selected mesh object or in a selected
subobject, such as a face. Refinement also resets the current smoothness
level to 0, so that the object can no longer be sharpened beyond
that level. Because refinement greatly increases the density of
a mesh, you might want to restrict this option to areas that require finely
detailed modification. Refinement also helps you mold smaller sections
with less effect on the overall shape of the model.
While highly refined
mesh gives you the ability to make detailed modifications, it also
comes at a cost: it can decrease program performance. By maintaining
maximum smoothness, face, and grid levels, you can help ensure that
you do not create meshes that are too dense to modify effectively.
(Use SMOOTHMESHMAXLEV, SMOOTHMESHMAXFACE, and SMOOTHMESHGRID.)
Set Mesh Properties Before
and After Creation
You
can set defaults that control a variety of mesh properties before
and after you create the mesh objects.
Mesh Primitive
Options dialog box. Sets the density of
the tessellation (the number of subdivisions) per dimension for
each type of mesh object you create.
Mesh Tessellation
Options dialog box. Sets the default settings
for 3D solid or surface objects that you convert to mesh. Options
define how closely mesh faces adhere to the shape of the object
and level of smoothness. You can also set the default to prefer
the settings in the Mesh Primitive Options dialog box for object
conversions.
Properties palette.
Modifies properties for both the mesh object and its subobjects
after they are created. For a selected mesh object, you can modify
the level of smoothness. For faces and edges, you can apply or remove
creasing, and modify crease retention levels.
Level of smoothness. By
default, the mesh primitive objects that you create have no smoothness.
You can change this default with the Settings option of the MESH
command. The modified smoothness value is maintained only during
the current drawing session.