NRB4SURF: Constructs a NURBS bilinear surface.
 
 Calling Sequence:
 
   srf = nrb4surf(p11,p12,p21,p22)
 
 INPUT:
 
   p11		: Cartesian coordinate of the lhs bottom corner point.
 
   p12		: Cartesian coordinate of the rhs bottom corner point.
 
   p21		: Cartesian coordinate of the lhs top corner point.
  
   p22		: Cartesian coordinate of the rhs top corner point.

 OUTPUT:
 
   srf		: NURBS bilinear surface, see nrbmak. 
 
 Description:
 
   Constructs a bilinear surface defined by four coordinates.
 
   The position of the corner points
 
          ^ V direction
          |
          ----------------
          |p21        p22|
          |              |
          |    SRF       |
          |              |
          |p11        p12|
          -------------------> U direction
 

    Copyright (C) 2000 Mark Spink

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

Demonstration 1

The following code

 srf = nrb4surf([0.0 0.0 0.5],[1.0 0.0 -0.5],[0.0 1.0 -0.5],[1.0 1.0 0.5]);
 nrbplot(srf,[10,10]);
 title('Construction of a bilinear surface.');
 hold off

Produces the following figure

Figure 1

Package: nurbs