Surface fails to build

There are two common reasons that a surface may fail to build. These will be reported by error message boxes:

• Missing intersections between curves - message appears Cannot build surface - Some intersections appear to be missing.

• Too few intersecting curves - message appears Cannot build surfaces - There are insufficient intersecting curves to define a surface.

• If no message boxes appear, but no surface is visible, check that one of the surface display modes is selected, and that the light bulb icons next to the patch names in the Patch View tree are on .