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);