1.1 --- a/README	Tue Oct 25 07:57:07 2011 +0300
     1.2 +++ b/README	Tue Oct 25 08:59:07 2011 +0300
     1.3 @@ -10,7 +10,8 @@
     1.4  
     1.5  2. Usage
     1.6  --------
     1.7 -The following snippet is sufficient to draw the surface of an implict sphere.
     1.8 +The following snippet is sufficient to draw the surface of an implicit unit
     1.9 +sphere, centered around the origin.
    1.10  
    1.11       struct metasurface *ms;
    1.12       
    1.13 @@ -27,7 +28,7 @@
    1.14       /* evaluator */
    1.15       float eval(float x, float y, float z)
    1.16       {
    1.17 -         return x * x + y * y + z * z;
    1.18 +         return (x * x + y * y + z * z) - 1.0;
    1.19       }
    1.20  
    1.21  See the examples subdirectory for more examples.