Angular Deviation

Check Spacing By

• Arc Length – Check the continuity at equally spaced points along the surface, determined by the Distance Between Checks option.

• Per Span – Check the continuity at a number of points in each span equal to the value of the Number Per Span option.

Dragging the also lets you interactively change the number of check points.

Distance Between Checks

The arc-length distance between continuity checks, when using the Arc Length option. The default is 10.0.

Number Per Span

The number of points in each span where continuity is checked, when using the # Per Span option. The default is 20.

Show Max Labels

If this option is toggled on, points of maximum tangency angle are shown. Note however that these labels only appear if part of the boundary has tangent discontinuities that are out of tolerance.

Show Edge Labels

If this option is checked, indicators showing areas of discontinuities are initially displayed along the boundaries. Red T labels indicate areas of maximum discontinuity. Blue T labels indicate areas of minimum discontinuity. Note: The labels are nor displayed if Show Comb is turned on.

Chain Select

If this box is checked, selecting a surface curve also selects all other surface curves that are tangent continuous with it.

Show Comb

Check on this option to see the comb lines for tangency breaks.

When on, you can right-click a comb sample in the viewport to display the deviation value at that point (see Display deviation values in the viewport.

Auto Scale

This option only appears if Show Combs is on. When Auto Scale is checked (default), the scale of the deviation combs is automatically calculated to be proportional to the size of the object.

When this option is unchecked, a Comb Scale option appears, allowing you to set the scale of the comb at the time of creation.

Comb Scale

A slider that allow you to adjust the scale of the combs at the time of creation. This value is only available if Auto Scale is turned off.

Dragging the also lets you interactively adjust the comb scale.

Check tangent continuity (G1) between surfaces that may not have positional continuity (G0)

1. Select the Angular Deviation tool .

2. Select the boundaries between two sets of surfaces by clicking them in turn (the pick chooser may appear), or box-selecting them. All the surfaces in a set must be connected. Additionally, if they are tangent continuous, they can be selected all at once by turning on Chain Select in the control window.

   Note: You can select surface edges, trim edges, and surface curves.

3. Click the Accept button that appears in the view window.

   A G1 locator is displayed, showing a green T if tangent continuity is achieved, or a yellow T if it is not. By default, the maximum angular deviation between the surfaces is displayed, as well as edge labels. You also have the option of displaying a comb showing the magnitude of tangency breaks along the boundary.

4. Click Next in the control window to check tangent continuity between another set of surfaces.

An example

Below are two sets of surfaces. The Surface Continuity tool shows that the longer surface fails to achieve positional continuity with its neighbors (top). The Angular Deviation tool can still be used to check tangent continuity and show angular deviation between those surfaces (bottom).

What if...?

I want the comb plots on all the surfaces to use the same scale

1. In the Evaluate tool palette, shift-select the Surface Continuity tool .
2. Turn on Show Combs and turn off Auto Scale.
3. Enter the scale factors for Positional, Tangent, and Curvature deviation combs respectively in the three Scale fields.

I want to change the tolerances?

Choose Preferences > Construction Options and open the Tolerances and Continuity sections.

The calculation takes too long?

1. In the Evaluate tool palette, shift-select the Continuity > Surface Continuity tool .
2. Increase the Distance Between Checks setting to make the tool calculate fewer sample points.