A Point Cloud is a data structure used to represent a collection of multidimensional points and is commonly used to represent 3D data. In a 3D Point Cloud, the points usually represent the x, y, and z geometric coordinates of an underlying sampled surface. When the color information is present, the Point Cloud becomes 4D.

Point Clouds can be acquired from hardware sensors (such as stereo cameras, 3D scanners, or time-of-flight cameras). It can be generated from a computer program synthetically. PCL supports the OpenNI 3D interfaces natively; thus it can acquire and process data from devices (such as Prime Sensor's 3D cameras, Microsoft Kinect, or Asus XTion PRO).

PCL will be installed along with the ROS indigo full desktop installation. Let's see how we can generate and visualize Point Cloud in RViz, a data visualization tool in ROS.