plane_coefficients(3)

NAME
plane_coefficients - calculate the coefficient form for a plane

SYNOPSIS
#include <matvec.h>

void plane_coefficients (const float *p, const float *q, const float *r, float *co);

DESCRIPTION

Given three points, not colinear, which naturally form a plane, calculate the 4-vector form for the plane coefficients. The three points are passed as p, q and r. The coefficients are returned in vector co.

The four coefficients returned are respectively a, b, c and d in the standard plane equation:

a x + b y + c z + d = 0

(Note that many texts use - d, so be warned).

The normal (perpendicular) vector to the plane may be derived immediately: it is just (a, b, c). Note that the normal vector is not normalized!

Planes are unbounded: they stretch off to infinity in all directions. If what you really want are bounded convex polygons, then you need to use a c2lib "face".

AUTHOR
Richard Jones <rich@annexia.org>

LICENSE
GNU LGPL (see http://www.gnu.org/)

VERSION
c2lib-1.2.14