Patrick, I don't know about the line - you'll have to take a screenshot to get more explanation on that, but you should be able to get rid of the black/white by deselecting "Autocompute Intensity Bound" under the laser scan or point cloud topics. I don't know a lot about that parameter, and it may do something more useful on real laser data; in simulation it does seem to do weird things. -Gil -- E. Gil Jones (gjones@willowgarage.com) Research Engineer Willow Garage, Inc. 68 Willow Road Menlo Park, CA 94025 650.475.9772 On Sun, Oct 3, 2010 at 4:59 PM, Patrick Doyle wrote: > I've been stepping through the first PR2 arm motion planning tutorial > ( > http://www.ros.org/wiki/motion_planning_environment/Tutorials/Making%20collision%20maps%20from%20self-filtered%20tilting%20laser%20data > ) > and I have a couple of questions... > > When I first launch rviz_collision_tutorial_1.launch, I see a cluster > of points lit up roughly where I think it's reasonable that the laser > scanner should be getting returns from the pole. When I launch > laser-perception.launch, I see that series of points traverse down the > pole, lighting up the tips of the grippers along the way. The cluster > of points on the grippers turn black about 1/2 way down the gripper > and stay black as they traverse down the arm and back up again, where > they turn white once again. Similarly, the clusfer of points on the > pole dim about 1/2 way down and, as best as I can tell, at exactly the > same time that the cluster of points on the grippers turn dark. They > turn bright again when the scan goes back up the pole. > > After the scan has traced all (or most?) of the way down the pole, I > see a very straight white line trace diagonally down across the rviz > scene, change direction, and go back up again, followed shortly after > by the cluster of points traversing the pole and the arms. > > Do other folks see similar behavior? If so, what causes the laser > scan display to turn dark (or dim) and what causes the straight white > line? > > When I first saw the straight white line, I thought it was the laser > scan itself, but now that I've run it a few times and understand (most > of the rest of what) I'm seeing, I'm not sure what the source of it is > (except that it is related to the laser scan itself). I see the > behavior of the white points turning dark/dim for both the laser scan > topic and the point cloud topic. > > --wpd > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users >