How to use nodelets in ROS

Posted by Megacephalo on
URL: http://official-rtab-map-forum.206.s1.nabble.com/How-to-use-nodelets-in-ROS-tp671.html

Hi,

I've been reading RTABMap_ros ROSWiki about the nodelets, and the official tutorials on nodelet, but still left some qustions unanswered. Would you kindly clear my doubts?

1. How do you use Rtabmap nodelets in Launch files? Why some of these nodelets depend on a manager and others are simply "standalone nodelets"? What are the differences between these two kinds?

2. On ROS documentation, it says that nodelets are C++ nodes which are designed to provide a way to run multiple algorithms on a single machine, in a single process, without incurring copy costs when passing messages intraprocess. If that is the case, ROS' very own framework should have resolved copy cost issue in the first place, left me wondering what true role nodelets play here?

3. What is/are the reason(s) that you developped certain functionalities as nodelets and others as nodes? Is it because you can implememt several functiomalities within a single nodelet for effective maintanence?

These are my questions on nodelets. Your answers mean so much to me. Thank you in advance!