openni_tracker failed because of InitFromXml failed
Hello ,I am a new user of ROS openni. Now I'm using ubuntu 12.04 and my ROS dist is groovy. when I run the command rosrun openni_tracker openni_tracker,the only thing I got is a error message: InitFromXml failed: Can't create any node of the requested type!
I followed several solutions on the ROS community,still get the same error message
I googled a lot ,but not a correct solution for me.Any help will be appreciated ,It really drives me crazy.
just like this link http://answers.ros.org/question/9737/openni_tracker-initfromxml-failed-cant-create-any-node-of-the-requested-type/.But It won't help
Can anybody help me?