Hey Todd, what exactly is the question, you do not understand the code? Can you post the whole h/cpp files? Do you have some laser scan data in a bag file we could try the code on? cheers, On Wed, Mar 17, 2010 at 5:00 PM, Todd Anderson wrote: > Hello, I am trying to use the point cloud on laser data... but the > transform/frame stuff is messing with me.  I want to be able to get points > with reference to the robot and points with reference to the fixed frame > map.  Currently I am looking up the transform between base_laser_link and > odom which outputs points in a manner that is beyond my spatial > understanding.  Here is the code: > static tf::TransformListener tf_listener; >   //const sensor_msgs::LaserScan::ConstPtr msg_in_myframe = > tf_listener.transformPoint( >   // Get the transform from the laser frame to the odometry frame >   tf::StampedTransform transform; >   try { >     tf_listener.lookupTransform(msg->header.frame_id, "odom",  ros::Time(), > transform); > >     // Turn the laser scan into a point cloud, in the odom coordinate frame >     sensor_msgs::PointCloud point_cloud; >     laser_projection.transformLaserScanToPointCloud("odom", *msg, > point_cloud, tf_listener); > >     for(vector::iterator it = > point_cloud.points.begin(); it != point_cloud.points.end(); ++it) >       ss << it->x << ' '<< it->y << endl; >   } catch (tf::TransformException &ex){ >     ROS_ERROR("%s", ex.what()); >   } > -- > Todd Anderson > (919) 710-0546 > Washington University in St. Louis Class of 2011 > School of Engineering and Applied Sciences > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > > -- MSc. Dejan Pangercic PhD Student/Researcher Computer Science IX Technische Universität München Telephone: +49 (89) 289-17780 E-Mail: dejan.pangercic@in.tum.de WWW: http://ias.cs.tum.edu/people/pangercic