When you click on the Tolerance Model button
on the Model Editing toolbar, CopyCAD displays the Tolerance Model dialog box.
This dialog box allows you to reduce the number of points, scanlines or triangles.
Tolerancing a scanline model will reduce the number of points in each scanline by chord tolerancing. The chord tolerance is the maximum deviation of a straight line from the original data.

Note: For regular grid data, better results are usually produced by applying a reduction tolerance during triangle generation rather than tolerancing scanlines
Click on one of the links below to find out more about that area of the dialog box.