Steven Anson Coons (1912-1979): American computer engineer.

 

Given four arcs parametrized on [0,1]  such that  The Coons patch is the surface parametrized by  where ,  and  so that .

The Coons patch provides a method to construct a surface supported on a given contour, when the latter is composed of 4 arcs of curves.

Examples:

First ruled surface parametrized by M1   joining points P1(t) to  points Q1(t).	Second ruled surface parametrized by M2 joining points P2(u) to points Q2(u).	Bilinear patch parametrized by M3 , portion of hyperbolic paraboloid  lying on the quadrilateral ABCD. The patch is flat if the 4 vertices are coplanar.	Final Coons patch  M1 + M2 - M3
		Edge formed by 4 arcs of circles of the same radius	We get a Bohemian dome

 
 
 

Production of a sphere thanks to Coons patches

Egg made by assembling Coons patches made by Alexandre Demir, for the best worker in France prize.

See also the Bezier surfaces.
 

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© Robert FERRÉOL  2017