Graphics Programs Reference
In-Depth Information
Converting Back to Polygons
Most models created with subdivision surfaces should be converted back to polygons
after the modeling is finished and rendering setup is ready to begin. Because subdivi-
sions are a more intricate surface type than polygons, you'll probably have better perfor-
mance while animating if you work with a polygonal model rather than a subdivision.
Professionals frequently use subdivision tools and surfaces to create their models but
then convert back to polygons after they're finished to avoid excessive memory usage
while rendering.
This is a simple procedure, similar to the earlier exercise in which you converted
NURBS surfaces to polygons. Here you'll convert the kettle back to polygons:
1. Select the subdivision kettle and its handle, spout, and lid, and choose Modify
➔
Convert
➔
Subdiv to Polygons
r
to open the Options box shown in Figure 5.98.
Figure 5.98
The Convert
Subdiv to Polygons
Options box
2. Select Adaptive for Tessellation Method. This option usually yields the best results.
3. The Divisions Per Face slider controls how smoothly the object is converted to poly-
gons. For the best results, select each piece of the kettle separately and convert the
pieces one by one, adjusting the Divisions Per Face value appropriately. A division
value of 2 will work for everything but the handle, which requires a division value
of at least 3 to remain fairly smooth.
At a division factor of 1, your kettle will look jagged. Turn it up to 2, and you'll notice a faithful
conversion to polygons.
More often than not, you'll want to take a model as far as possible before you convert
it to polygons, but you should always save the original subdivision version in case it needs
to be modified. This way, you can revert to your subdivision file, make your changes, and
reconvert to polygons to render out the changes.
