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1258 Chapter 9: Sur face Modeling
item. Double-clicking the object name in the list
perfor ms the same function.
Threshold Units group
The options in this group box let you choose
between two types of t hreshold units. Switching
between these two options does not alter the
effect; it alters the method by which you set the
thresholds.
Pixels—The t hresholds are determined by
specifying the m aximum pixel size of the image
(measured diagonally). Use when you want to set
the transfer thresholds using absolute rather than
relative values.
% of Target I mage—Sets the thresholds based on
the percent age of the size of the image (measured
diagonally) relative to the size of the rendered
output.
Thresholds group
Min Size/Max Size—Sets the minimum s ize of the
object before it’s replaced by the less complex
object, and the maximum size of the object before
it’sreplacedbythemorecomplexobject. The
values vary depending on the current type of
Threshold Unit. The default threshold values are
initi alized so that the most complex object is 100
percentoftheimageoutputsize. Theremaining
thresholds are set using a n algorithm based on a
ratio of the number of faces between each object.
Itassumesthatallfacesarethesamesize,andthen
picks thresholds so that the faces would remain a
constant size as displayed on the screen. Usually,
this will provide the type of s m ooth transition you
need, but you can customize the threshold va lues.
The threshold va lues are interrelated b etween
the objects, so altering the minimum size of one
object, for example, will also alter the maximum
size of the next object.
Reset All—Resets all thresholds for all objects in
the list, using the previously described algorithm.
Tip: You can use the Le vel of Detail utility to create
objects that display very simple geometry in the
viewports, while displaying complex geometry
in the rendered scene. Create a grouped Level
of Detail object consisting of only two objects,
the complex object and the simple object. Select
thesimpleobjectinthelistwindowand,inthe
Thresholds are, set its Min Size and its Max Size
to 0. This will display the simple object in the
viewports, but the complex object will always
appear in the rendered scene, regard less of its
apparent size.
Close button
Clo se—Closes the utility.