Autodesk LIGHTSCAPE, Manual

Page: 72 / 362

Importing Geometry 5
64
Lightscape
By Entity
Select this option to create a block for each DWG
entity. However, faces will be imported as surfaces
(not grouped into blocks).
Setting Geometry Options
Use these options to control how layers and geom-
etry are imported into Lightscape.
Skip Off and Frozen Layers
Enable this option if you do not want to import
layers that are turned off or frozen.
Cap Closed Entities
Enable this option to close the top and the base of
entities that have thickness. Entities that have no
thickness will be converted to surfaces when
imported.
Number of Arc Segments
Use this option to set 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.
Smoothing Groups
Enable this option to convert thick 2D polylines and
3D polygon and polyface meshes to quadrilaterals in
a smoothing group. If facets are part of a smoothing
group, Lightscape can create a smooth curved
appearance between these facets when they are
displayed and rendered. For more information, see
“Translating Geometry: Smoothing Groups” on
page 58.
Angle Between Normals
If Smoothing Groups is enabled, use this option to
establish a threshold at which adjacent facets in a
smoothing group should be rendered with sharp or
smoothed edges. If the angle between 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.
ACIS Surface Deviation
Use this option to set the amount of surface devia-
tion when importing ACIS geometry.
Using Block and Luminaire Libraries
When you import a DWG file, you can map pre-
existing Lightscape block and luminaire definitions
to incoming DWG blocks of the same name.
Saving blocks to a block library ensures that each
time you load a DWG file, the geometry does not
need to be prepared again in the subsequent Prepa-
ration stage.
For information on working with luminaires, see
Chapter 8, “Artificial Lighting.” For information on
working with blocks, see Chapter 6, “Refining
Geometry.”