About Working With Mesh Models

    About Working With Mesh Models

    Learn some best practices for mesh modeling.

    Mesh modeling, with its enhanced modeling capabilities, offers a way to create more
    fluid, free-form designs. Keep these tips in mind as you work.

    Model a mesh before you smooth it.

    Mesh modeling is a powerful way to design, but higher levels of smoothness increase
    complexity and can affect performance. You can work more efficiently if you complete
    editing operations such as gizmo editing, extrusion, and face splitting, on mesh objects
    that have not been smoothed. (That is, their level of smoothness is 0.)

    mesh sphere modeled by grip editing and extrusion, then smoothed

    You can quickly switch between the levels of smoothness in the Properties palette
    to get a preview of how your activities affect the smoothed mesh.

    Refine or split a face instead of refining the entire mesh.

    Refinement is a powerful way to subdivide faces. However, by increasing the number
    of faces, you add to the overall complexity of the model. In addition, refining an
    entire mesh object resets the base level of smoothness to 0. This change can result
    in a dense grid that can no longer be simplified. For best results, avoid refining
    the object, and refine or split only the individual faces that require more detailed

    mesh box, refined mesh box, and mesh box with one face refined

    Refining individual faces does not reset the level of smoothness for the object.

    Crease edges to help limit distortion when the mesh is smoothed.

    Creased edges can be set to maintain their sharpness, no matter how much the mesh
    is smoothed. You may also need to crease the edges in surrounding faces to obtain
    the result you want.

    extruded faces on mesh torus, creased and not creased

    Creasing set to Always retains its sharpness after smoothing. If you set a crease
    value, the creased edge becomes smoother at the equivalent level of smoothness.

    Use gizmos to model faces, edges, and vertices.

    3D Move, 3D Rotate, and 3D Scale gizmos can be used to modify entire mesh objects,
    or specific subobjects.

    For example, you can rotate and scale an individual face using the 3D Move, Rotate,
    and Scale gizmos.

    By constraining the modifications to a specified axis or plane, gizmos help you avoid
    unexpected results. The default gizmo is displayed whenever you select an object in
    a view that uses a 3D visual style. (You can also suppress this display.) Therefore,
    you do not have to explicitly start the 3D Move, 3D Rotate, or 3D Scale command to
    initiate these activities. You just need to select an object.

    When a gizmo is selected, you can use the shortcut menu to switch to a different type
    of gizmo.

    Use subobject selection filters to narrow the available selection candidates.

    In a smoothed mesh, trying to select a subobject can be difficult unless you turn
    on subobject selection (shortcut menu). By specifying that the selection set is limited
    to faces, edges, vertices, or even solid history subobjects, you can restrict which
    subobject type is available for selection.

    mesh faces selected when the face subobject selection filter is on

    A filter is valuable for selecting mesh vertices, which are not highlighted as you
    move over them.

    To select the entire mesh object, turn off the subselection filters.

    Model by extruding faces.

    A key difference between gizmo editing and extrusion occurs in the way each face
    is modified. With gizmo editing, if you select and drag a set of faces, adjacent faces
    are stretched to accommodate the modification. When the object is smoothed, the adjacent
    faces adapt to the new location of the face.

    mesh faces extended using 3D Move gizmo

    Mesh extrusion, however, inserts additional faces to close the gap between the extruded
    face and its original surface. With mesh extrusion, you can set whether adjacent faces
    are extruded as a unit (joined) or separately (unjoined).

    mesh faces extruded, then smoothed

    If you are working on an object that has not been smoothed, try smoothing it periodically
    to see how the extrusion is affected.

    Convert between mesh and 3D solids or surfaces.

    Mesh modeling is powerful, but it cannot do everything that solid modeling can do.
    If you need to edit mesh objects through intersection, subtraction, or union, you
    can convert a mesh to a 3D solid or surface. Similarly, if you need to apply creasing
    or smoothing to a 3D solid or surface, you can convert it to a mesh.

    Keep in mind that not all conversions retain complete fidelity to the shape of the
    original object. Avoid switching between object types more than once, if possible.
    If you notice that the conversion modifies the shape of the object in an unacceptable
    way, undo the conversion and try again with different settings.

    The Mesh Tessellation Options dialog box (MESHOPTIONS) controls the smoothness and
    shape of the faces for 3D solids or surfaces that are converted to meshes. Although
    you can convert an object to a mesh without opening this dialog box (MESHSMOOTH),
    you can more easily experiment with different conversion settings by launching the
    conversion operation from within the dialog box.

    The MESHSMOOTHCONVERT system variable sets whether the mesh objects that you convert
    to 3D solids or surfaces are smoothed or faceted, and whether their co-planar faces
    are optimized (merged).

    You might have trouble converting some non-primitive mesh to solid objects due to
    the following problems:

    • Gaps in the mesh. If you notice gaps, you can sometimes close them by smoothing the mesh or by refining
      the faces that are adjacent to the gap.

      mesh torus that has been twisted using 3D Rotate at various smoothing levels

      You can also close holes by using MESHCAP.

      In some cases, you can also obtain better results by using hardware acceleration to
      improve your graphics system.

    • Intersecting mesh faces. Be especially careful not to create self-intersections as you move, rotate, or scale subobjects. (You create self-intersections when you
      cause one or more faces to cross or intersect other faces in the same mesh model.)
      View the mesh from several viewpoints to ensure you create a viable model.

      mesh wedge with front faces dragged past the back faces

    Mesh objects that cannot be converted to solids can often be converted to surfaces

    Avoid merging faces that wrap a corner

    When you merge faces, you can create a mesh configuration in which the merged face
    wraps a corner. If a resulting face has a vertex that has two edges and two faces,
    you cannot convert the mesh to a smooth 3D solid object.

    One way to resolve this problem is to convert the mesh to a faceted solid instead
    of a smooth solid. You might also be able to repair the problem by splitting the adjacent
    faces, starting at the shared vertex (MESHSPLIT).

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