ravi's profile - activity

You should have the color transformer set to flat and then be able to choose a color for the pointcloud in rviz.

Your problem is that you have a bag file with different message versions than the code you are running. Usually the bag files were recorded in a past version of ROS and are incompatible. You should be able to use rosbag fix to fix the bag files.

It's not sufficient to just change the metadata (i.e. angle_min/max) in the laserscan. You need to modify the laserscan data itself to remove the points you wish to filter.

Hi all,

I am using Matlab to get laser_scan from laser 2d scan LMS and then I am publishing it to convert it to point cloud, but I am getting error in frame, I do not know in which frame I should convert it into point cloud, please help me in getting the solution.

There are conversions between ROS data types and some mrpt data types in the mrpt-ros-pkg repo

The documentation is quite spares, but I do remember seeing conversion methods which you could use in a custom program.

In the turtlebot stack there is a pointcloud_to_laserscan package that includes a nodelet cloud_to_scan that iterates through a pointcloud to produce a laserscan. This is a bit backwards to what you are trying to do but with a bit of mixing things around it should be a good start.

I am playing the bag and trying to subscribe the topic /velodyne/rawscan in a program and print the subscribed input on stdout, but I get the errer and even after using "rostopic echo /velodyne/rawscan" while playing bag I get the following error: [ERROR] [1308109245.015874373]: Client [/rostopic_13899_1308109244719] wants topic /velodyne/rawscan to have datatype/md5sum [velodyne_common/RawScan/a36da642742ddd79774fbc755f9c5cdd], but our version has [velodyne_common/RawScan/d34cf5a37a401b668e53c57f6409eb76]. Dropping connection

Hi all,

I am trying to get velodyne rawscan from a input bag which publishes velodyne_common/RawScan (topic= velodyne/rawscan) but I get this error,

Waiting 0.2 seconds after advertising topics...

[ERROR] [1308039369.255405494]: Client [/my_3D_to_2D] wants topic /velodyne/rawscan to have datatype/md5sum [velodyne_common/RawScan/a36da642742ddd79774fbc755f9c5cdd], but our version has [velodyne_common/RawScan/d34cf5a37a401b668e53c57f6409eb76]. Dropping connection.

Please help me.

Edit: I am playing the bag and trying to subscribe the topic /velodyne/rawscan in a program and print the subscribed input on stdout, but I get the errer and even after using "rostopic echo /velodyne/rawscan" while playing bag I get the following error:

[ERROR] [1308109245.015874373]: Client [/rostopic_13899_1308109244719] wants topic /velodyne/rawscan to have datatype/md5sum [velodyne_common/RawScan/a36da642742ddd79774fbc755f9c5cdd], but our version has [velodyne_common/RawScan/d34cf5a37a401b668e53c57f6409eb76]. Dropping connection

Hi all,

I need 2d laser data of horizontal terrain, but I am unable in getting that, so I am using data from ( mrpt.org ), rawlog format but can any please tell me how to convert the rawlog file in to bag or input data.

I am using the latest version of ROS.

Hi all,

I am using RVIZ to visualize the point clouds I have obtained after applying certain methods, I am trying to visualize it along with the original point cloud but in different color, but I am unable to get different color even if I set the color of different point clouds. I am using latest version of RVIZ, please help me in getting the solution so that I can set the color of clouds. The color of grid and axes can be visualize easily.

Thanking You.

Hi,

I am using "laser.bag" to publish the laser scan and then I am taking a temporary pointer to the subscribed laser scan and changing the angle_min and max to reduce the point cloud obtained by function "transformLaserScanToPointCloud()", but it does not work. When I visualize my published point cloud in RVIZ and compare it with the original point cloud (i.e. without any angle change) then only the direction of point cloud in RVIZ changes there is no any compression/reduction in point cloud.

Help me in getting the solution.

Hi,

I am new in ROS and working on extracting constrained point cloud either from laser_scan directly or by first converting the laser_scan into point cloud and then constrained the point cloud to get the desired point cloud.

I am using laser.bag as laser_scan data and I am trying to change the angle_min and max from the already set values to a new desired values, for this I am using a new pointer to input from laser.bag and changed the angle value, but I am unable to get required result.

The angle min and max is -0.84... and 0.8... and I have changed it to -0.45 and 0.45 to get only point cloud in between the angle.

Please help me.

(the constrained is like getting only point cloud up to 10meter range from robot or getting point cloud only like between -45 to 45 while laser_scan is from -90 to 90).