public float pseudoDistance(Vector3f point) {
        return normal.dot(point) - constant;
    }
<code>pseudoDistance</code> calculates the distance from this plane to
a provided point. If the point is on the negative side of the plane the
distance returned is negative, otherwise it is positive. If the point is
on the plane, it is zero.

@param point
           the point to check.
@return the signed distance from the plane to a point.
jme3-core/src/main/java/com/jme3/math/Plane.java