Autodesk LIGHTSCAPE, Руководство пользователя

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Importing DXF Files
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Setting the Angle Between Normals
Use the Angle Between Normals to establish a
threshold at which adjacent facets in a smoothing
group should be rendered with sharp or smoothed
edges. If the angle between the normals (vector
perpendicular to the facet) of the adjacent facets
incident on a vertex is larger than the value of the
Angle Between Normals, the sharp edge is preserved
for that vertex.
Smoothing only affects the appearance between the
edges of adjacent polygons—it will not smooth the
profile of objects. To control the smoothness of the
profile, adjust the number of arc or curve segments.
Note: You can also create smoothing groups and
adjust smoothing after you import your model. For
more information, see “Smoothing Surfaces” on
page 98.
Number of Arc Segments
Use the Number of Arc Segments option to control
the number of straight line segments into which the
system divides arcs, circles, and arc segments in 2D
polylines.
Arcs are divided into a number of segments propor-
tional to their subtended angle. For example, an arc
spanning 180
°
is divided into half as many segments
as a circle.
Grouping Objects into Blocks
When you import a DXF file, the layering and block
structure of the DXF format is preserved.
In addition, you can organize top-level entities (enti-
ties not already included in a block) by grouping
them into blocks, as required.
Appearance if smoothing
angle is set to less than 45°
Angle Between Normals of the polygons is 45°
Appearance if smoothing
angle is set to greater than 45
Smoother profile: Circle
imported with Number
of Arc Segments set to 12. Coarser profile: Circle
imported with Number of
Arc Segments set to 6.
Arc imported with
Number of Arc
Segments set to 12. Arc imported with
Number of Arc
Segments set to 6.