RtColor tint[1] = { {randBetween(0.8,1),randBetween(0.8,1),randBetween(0.8,1) } } ;
            RtFloat gain[1] = { randBetween(0.2, 1.0) };
            RtFloat disp[1] = { randBetween(0.0,0.2) };
            RiSphere(radius, -radius, radius, 360, 
                                        "constant color Tint", (RtPointer)tint, 
                                        "constant float Gain", (RtPointer)gain, 
                                        "constant float Disp", (RtPointer)disp, RI_NULL);
            //RiSphere(radius, -radius, radius, circum, RI_NULL);