2009

surface is reduced to flat facets. For most applications and file formats,
you have control over the level of faceting that takes place.
All items, no matter what their size, will use the same faceting factor and
so have the same number of sides to curved entities. Therefore, you
need to experiment a little with different values to account for the size
that these items will appear on screen.
The faceting factor must be greater or equal to 0, where 0 results in the
faceting factor being turned off. The default value is 1, if you double the
value you get twice the number of facets, if you halve the value you get
half as many facets. Larger faceting factors will result in more polygons
to a model and larger NavisWorks files. There is little point having a large
faceting factor if these curved entities are golf balls viewed from 200
yards!
For AutoCAD exports, the faceting factor is set from the NWCOPT
command, MicroStation's faceting factor is set from Options, which is
available from the NWCOUT export dialog, and the option to set the
faceting factor on reading CAD files is found by choosing Tools, Global
Options, and the relevant options tab.
Max Facet Deviation
Maximum facet deviation is used in conjunction with faceting factor to
ensure that larger objects, with too large a deviation from the original,
have additional facets added. If a difference greater than the entered
value is found in a model it adds more facets. The values are measured
in the model units.
Where d is greater than the maximum faceting deviation value, more
facets are added to the object.
If the max faceting deviation is set to 0, then this function is ignored and
just the faceting factor is used.
Shape Merge Threshold
MicroStation shapes are polygons that can have 3 or more vertices.
They're often used to model more complex objects which can waste
memory. So, NavisWorks merges all shapes on the same level or in the
same cell and with the same color into a "Shape Set" if these shapes
have less than or equal to the number of vertices given by the Shape
Merge Threshold.
Selection Terminology
Glossary
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