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PolyCAD

3. There are not enough control points in either the column or row directions of the surface. It can be refined, inserting new columns and rows without changing shape using global subdivision. Global subdivision refines the BSpline surface knot vector by inserting multiple columns or rows so that the knot vector remains uniform. In the attributes panel, press the 'xU' to refine the surface in the u direction.

In the attributes panel, then number of column lines in the schematic display of the control polygon mesh increases.

4. Refine the surface in the V direction by pressing the 'xV' button.

The surface should now have five rows.

6. Edit the control points to create a more curved yacht hull section.

Forming the Bow Profile >>>