Assessing surface fairness

There are 4 surface display modes, all of which are useful for judging surface regularity and fairness. These are:

• Isophote display mode

• Smooth rendered display mode

• Isoparametric display mode

• Cut curves display mode

The selected surface display mode applies to all patches in all windows. There are two ways of controlling the display of individual patches:

In graphics views

1. Click the Right Mouse button on the patch to launch a popup menu.

2. Use DISPLAY CONTROL POINTS to toggle the display of the control points.

3. Use DISPLAY SURFACE to hide the patch surface, but not the control points, if these are visible.

In the Patch View tree

4. Expand the Patches node.

5. Select one or more patches by clicking on their name (for multiple selections hold <Ctrl>, contiguous selections hold <Shift>).

6. Select the Right Mouse button to launch a popup menu which presents three display options

7. Select TOGGLE SURFACE DISPLAY, TOGGLE CONTROL POINTS DISPLAY and TOGGLE TANGENCY CONTROLS respectively to display or hide the surface, control points and tangency controls for the selected patches.

Various options which affect the surface display modes are set using the Patch Display Settings dialog (select DISPLAY \ PATCH \ SETTINGS… or - see also Patch Display Settings Dialog). The Translucency setting controls the translucency of the surface, from 0% (opaque) to 100% (transparent). This only affects isophote and smooth rendered display modes. The settings in the Isophotes group are described in the next sub-section.