Zebra stripes analysis
Description: 2 minutes; Lab exercise: 5
minutes
Use the zebra stripes analysis tool to
detect small surface defects and transitions between faces.
In dialogs that create of modify b-spline surfaces, it is helpful to have a
tool to analyze the surface quality at any time. The Surface Analysis tool is
now available as a subdialog in various Surfacing dialogs. The Zebra stripes
analysis tool is available in the Skin, Bridge, Cap, Smooth and Modify Surface
dialogs.
Zebra stripes are a reflection of an imaginary striped sphere or cube.

Watch the stripes at the transition edge:
- If the stripes do not fit together (do not match up), this
indicates that the transition between the two faces is not smooth.

- If the stripes do fit together (match up) and have a clear
angle, this indicates that it is a tangential transition.

- If the stripes fit together (match up) at no angle, there
is a "near" curvature continuous transition. Because the Zebra stripes are an
optical analysis, a curvature continuous transition is not certain and must be
considered "near."

Facet refinement
The Facet Refinement option of the Surface Analysis subdialog is a temporary
refinement of the facet model of the selected parts or faces. A better model
resolution can lead to a better analysis result. (You can see the facet model by
turning on Wire in the Show menu.) Extreme facet refinement will reduce system
performance.
A facet refinement setting is effective only during the current analysis.
Limitations
- Select faces or parts manually only when using the Surface
Analysis tool (not when using Surface Analysis in the Surfacing menus).
- When selecting new faces or parts in the Surface Analysis
tool, it is not possible to have the subdialog open.
- No package files are provided for this lab.
Lab exercise
You will need to load a model that has two connected surfaces.
To conduct a face to face transition analysis:
- Click Surfacing
.
- Click Surf Analysis
in the Tools section.
- Specify the Type
of analysis: Zebra stripes.
- Specify the Faces or Parts over which the analysis is to
be performed. Neighbor faces are automatically selected for analysis. A
preview of the selected faces is displayed.
- Select the type of
Display Parameters: Spherical
or Cubical. The display parameter
determines whether the stripes are reflected as spheres or as cubes.
- Change the thickness of the zebra stripes by moving the
tab in Stripe Number.
- Change the ratio of stripe colors by moving the tab in
Color Ratio.
- To modify the facet model of the selected faces, use the
Facet Refinement list. The refinement
is temporary; the normal facet is returned when the analysis is completed.
- Continue to adjust analysis parameters, or click
to finish the surface analysis.