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Importing AutoCAD Drawing Files 539
change the height se gments, capping options, and
height value.
When off, objects with thickness (and closed
capped objects) are converted directly to a mesh.
Create One Scene Object For Each ADT
Object—
Architectura l Desktop (ADT) objects
are imported as a single object instead of being
separate d into their constituent components. This
means that if you import an ADT door object, the
door is represented as one object instead of three.
Turningonthisswitchmakeimportingfasterand
the scene size is sma l ler.
Note: This switch presents several modeling
concerns that you should be aware of:
• Material assignments from ADT are not
translated during the import process..
• If you want to assign materials to these objects,
you’ll have to use Multi/Sub-Object materials.
• Dependi ng on the Texture Mapping option
you choose, UVW coordinates are translated
correctly.
Weld —Sets whether coincident vertices of
converted objects are welded, according to the
Weld Threshold setting. Welding smoothes
across seams and unifies normals of objects with
coincident vertices.
Weld Thresho ld —Sets the distance that determines
whether v ertices are coincident. If the distance
between two vert ices is less than or equal to the
Weld Threshold, the vertices are welded together.
Auto-smooth—Assigns smoothing groups
according to the Smooth Angle value. Smoothing
groups determine whether faces on an object
render as a smooth surface or display a seam at
their edges, creating a faceted appearance.
Smooth Angle—Controls whether smoothing
occurs between two adjacent faces. If the angle
betweenthetwofacenormalsislessthanorequal
to the smooth angle, the faces are smoothed.
Unify Normals—Analyzesthefacenormalsofeach
object and flips normals where necessary, so they
all point out from the center of an object. If the
imported geometry is not properly welded, or if
the software can’t determine the object’s center,
normals might be oriented in the wrong direction.
Use the Edit Mesh or Normal modifiers to flip
normals.
When Unify Normals is turned off, normals are
calculated according to the face vertex order in
the drawing file. Face normals for solid objects
are already unified. Turn off Uni fy Normals when
importing drawings containing solid objects.
You should also turn off Unify Normals when
working w ith Architectural Desktop files.
Cap Cl osed Objects—Applies an Extrude modifier
to all closed objects, and turns on the Cap Start
and Cap End options of the modifier. The E xtrude
modifier Amount va lue for a closed entity with no
thickness is set to 0. Capping makes closed entities
with thickness appear solid a nd closed entities
without thickness appear flat. When Cap Closed
Objectsisturnedoff,theExtrudemodifierCap
Start and Cap End options for closed entities with
thickness are turned off. No mo difiers are applied
to closed entities without thickness, except for
Circle,Trace,andSolid.
Note: If Use Extrude Modifier to Represent
Thickness is turned off, an extrude mod ifier is
not
appliedtoclosedobjects.
Texture Mapping—The texture mapping
settings affect the lo ading time of models that have
many objects with stored UVW Coordinates for
texture mapped materials.
Note: This setting only applies to geometry that
is stored as a mesh in the scene. Spline shapes
marked as renderable have separate controls
for UVW coordinate generation on the Spline
Rendering panel.