remove unnecessary using namespace, minor updates
remove unnecessary using namespace, minor updates

wilsonCernWq/ospray,ospray/OSPRay,MengjiaoH/ospray,ospray/OSPRay,wilsonCernWq/ospray,MengjiaoH/ospray,ospray/OSPRay,ospray/OSPRay,MengjiaoH/ospray,MengjiaoH/ospray,MengjiaoH/ospray,wilsonCernWq/ospray