//¤@­Ócheck½d¨Ò

//==========================================================

//      ground plane

surface {                                

        texture {                        

                pattern checker          

                scale 5 5 0              

                surface { diff blue }    

                surface { diff red }     

        }                                

}                                        

ring {                                   

        center 0 0 -2                    

        normal 0 0 1                     

        radius 100                       

     }

//==========================================================