Creating a Point Cloud surface by specifying four vertices

In the following step-by-step example you will create a surface starting from a point cloud and specifying four vertices.
Please note that you can accomplish this task by loading sample file "sr0208.e3".

1	Start the Point Cloud command.
2	If not already selected, in the Surface Type drop-down list select Fit cloud of points.
3	In the Input Mode drop-down list, choose Select.
4	Using a window selection, select the points to be fitted and end selection by right-clicking and choosing Continue in the context menu.
5	In the Fitting Mode drop-down list, select 4 Vertices
6	Select the four vertices as in the following picture.
7	Under NURBS parameters, set the values for the resulting surface. For example set the following: Deg. U 3 Cont. U 2 Deg. V 3 Cont. V 2 Arcs U 1 Arcs V 1 Click the Preview button ( ). The preview of the resulting surface is displayed: The fitting parameters are also displayed: Max. distance the distance of the point that is farthest away from the fitting surface, which you can display by selecting the Most distant point check box. Mean square error Let di be the distance of the point Pi from the fitting surface and n the number of points to be fitted. The mean square error Eqmis the following:   You can iterate the fitting process by clicking Mean square error, thus reducing the above said values. The number of iterations can also be set (in the No. of iterations box). You can have a preview of the control points for the resulting surface by checking the Show Control Points box.
8	Click or to confirm your selections and create the surface. Click to discard your changes.