Parsing 3D txt data set

edit

Hello!I've obtained a 3D data set and its stored in a txt file, the question would be how it is possible to load it into RViz? Thank you.

Im trying to build up a PointCloud message, the 3D data set is loaded from a vector, im stucked how to insert the values of pC into cloud.channels.values. In this way there is no msg reeived in RViz.

sensor_msgs::PointCloud cloud;
    cloud.header.stamp = ros::Time::now();
    cloud.header.frame_id = "/base_link";

    cloud.channels.resize(1);
    int32_t countX = 24120;
    int32_t countY = 24120;
    int32_t countZ = 24120;
    int32_t total = countX * countY * countZ; 
    cloud.points.resize(total);

    cloud.channels[0].values.resize(total);
    cloud.channels[0].name = "rgb";     

    while (it < myvector.end())
    {
          geometry_msgs::Point32& pC = cloud.points[i]; 
          pC.y = *(it) * 0.001;
          myfile2 << *(it++) * 0.001 <<"\n";
          pC.x = *(it) * 0.001;
          myfile2 << *(it++) * 0.001 <<"\n";
          pC.z = *(it) * 0.001;
          myfile2 << *(it++) * 0.001 <<"\n";

          cloud.channels[0].values[i++] = 1.0f;                       
     }
     myfile2.close();
     cloud_pub.publish(cloud);