DIRECTIONS:   In this applet, you create a triangular Coons patch by dragging the control points for the edge curves to an appropriate location creating the edge curves as Bezier curves. You drag the point in perspective view on the image plane and move the point in and out of the image plane by using the A and Z buttons where A moves point directly on a line towards your eye so the point will not move apparently on the image screen and Z moves the point directly on a line away from your eye. Alternatively, you can move the point using the C and D buttons perpendicularly to the image plane, C moves away from you and D moves the point toward you. The patch can be rotated using the arrow keys, and you can zoom out and zoom in using the page up and page down keys.

There are two options for creating the patch, linear blending or cubic blending. This is selection by checking the cubic method. As in the Triangular Bezier patches, you can look at the points on the patch as created through an affine combination.