Automatic Reparameterization (Graphic)

Here's an example of two curves with an unequal number of points.

$image\surf_matrix_reparam1_shg.gif$

When the EZ-CAM application places additional points along the curves, it calculates the position of each point as a percent of the total curve length. A point is then placed on the next curve in the surface at the same position along the curve. These points are then connected by a link in the surface. This may result in unevenly placed surface patches, and inconsistent machining. (Note the closely spaced links in the center of the surface in the figure below.)

$image\surf_matrix_reparam2_shg.gif$

To control the interpolation and reparameterization process, the Blend Tolerance parameter, found in the Preferences portion of the Setup dialog box, sets a tolerance band around each point along the selected curves. The Blend Tolerance value is entered as a percent of the total curve length. Points that fall within the tolerance band are connected instead of creating new points which may result in error-prone surfaces. The figure below shows an example of connecting two points that fall within the tolerance band. The points at 47% and 50% are connected instead of placing new points on each curve as shown in the figure above.

$image\surf_matrix_reparam3_shg.gif$

The Blend Tolerance value must be entered as an integer from 0 to 100 (the default value is 10%). To turn this feature off and force the EZ-CAM application to insert equal points everywhere along the curves, enter 0 for the Blend Tolerance. The Blend Tolerance parameter may be changed after a surface has been created. To recreate the surface with the new Blend Tolerance, select the Update Last command in the Surface menu.

Note

When each curve selected to create a surface contains the same number of points, the system does not make any changes, either moving, or inserting points. Thus, to control the shape of the surface completely, you can define all required points on each curve. Also, points are not generated in Coons Surfaces at locations where transverse and longitudinal curves intersect. These points must be user-defined.