■ Common Problems When Moving into Maya 327
Click the Cleanup button, and this will resolve any of the issues that often arise when
modeling with the Extrude tool. Cleaning up your mesh now can save a lot of head-
aches later on.
Troubleshooting Renders and Artifacts
In some cases you may see artifacts in your renders. If you
see bloating in your render, that means there is a mistake
with the Alpha Gain and Alpha Offset values or the Alpha
Detection setting is wrong (Figure 9.48). Usually you have
forgotten to set one or both, or the Alpha Offset is not set to
–½ Alpha Gain.
Small spikes on UV seams can be remedied by using
the Smooth UV option under Tools → Displacement. Use
this only when creating an adaptive map. It has no effect in
DPSubPix mode. Many artifacts are caused by bad topology
in the underlying mesh. Triangles, poles, or faces with more
than four sides can result in surface errors (Figure 9.49).
These artifacts should be hidden in inconspicuous places
during the modeling process or removed completely. If you
find such an artifact on your render, applying a smooth to
the mesh before rendering can help (Figure 9.50). Doing so
will increase render time, and you may want to lower your
Approximation settings as a result.
Figure 9.47 Cleanup Options dialog box
Figure 9.48 The bloating in this render is due to incor-
rectly set Alpha Gain and Alpha Offset settings.
Figure 9.49 An example of problematic topology