Real myamount = func(cache,r);
//if(myamount<0.0)myamount=0.0;
//if(myamount>1.0)myamount=1.0;
myamount *= get_amount();
(*surface)[j][i] = Color::blend(color,(*surface)[j][i],myamount,get_blend_method());
Real myamount = func(cache,r);
//if(myamount<0.0)myamount=0.0;
//if(myamount>1.0)myamount=1.0;
myamount *= get_amount();
(*surface)[j][i] = Color::blend(color,(*surface)[j][i],myamount,get_blend_method());