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
Methods for Creating Mesh
You
can create mesh objects using the following methods:
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.
To set the maximum smoothness
level for mesh objects
- At the Command prompt, enter smoothmeshmaxlev.
- Enter a value from 1 to 255.
(Use lower numbers to
prevent extremely dense meshes that might affect program performance.)
To set the maximum number
of faces for mesh objects
- At the Command prompt, enter smoothmeshmaxface.
- Enter a value from 1 to 16,000,000.
To control the display
of the mesh facet grid
- At the Command prompt, enter smoothmeshgrid.
- Set the smoothness level at which the
mesh object displays the underlying facet grid:
- 0 hides the
display of the underlying facet grid.
- 1 displays the
facet grid for smoothness levels 0 and 1.
- 2 or higher specifies
the highest level of smoothness at which the facet grid is displayed.
To change the default level
of smoothness of new mesh primitive objects
- At the Command prompt, enter mesh.
Then enter se (SEttings).
- Enter a smoothness value and press Enter.
(A smoothness level of
5 or less is recommended.)
- Press Esc to end the command or specify
a mesh primitive type to create.
The smoothness value
is retained for the current drawing session.
Commands3DFACE
Creates
a three-sided or four-sided surface in 3D space.
3DMESH
Creates
a free-form polygon mesh.
EDGESURF
Creates
a mesh between four contiguous edges or curves.
MESH
Creates a 3D mesh primitive
object such as a box, cone, cylinder, pyramid, sphere, wedge, or
torus.
MESHOPTIONS
Displays the Mesh Tessellation
Options dialog box, which controls default settings for converting
existing objects to mesh objects.
MESHPRIMITIVEOPTIONS
Displays the Mesh Primitive
Options dialog box, which sets the tessellation defaults for primitive
mesh objects.
MESHSMOOTH
Converts 3D objects
such as polygon meshes, surfaces, and solids to mesh objects.
PFACE
Creates a 3D polyface
mesh vertex by vertex.
PROPERTIES
Controls properties
of existing objects.
REVSURF
Creates
a mesh by revolving a profile about an axis.
RULESURF
Creates
a mesh that represents the surface between two lines or curves.
TABSURF
Creates a mesh from
a line or curve that is swept along a straight path.
System VariablesSMOOTHMESHMAXLEV
Sets the maximum smoothness
level for mesh objects.
SMOOTHMESHMAXFACE
Sets the maximum number
of faces permitted for mesh objects.
SMOOTHMESHGRID
Sets the maximum level
of smoothness at which the underlying mesh facet grid is displayed
on 3D mesh objects.
VSEDGES
Controls the types of
edges that are displayed in the viewport.