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Clearing operation in costmap_2d explanation ?

asked 2014-08-21 13:05:45 -0500

2ROS0 gravatar image

Can someone explain the following sentence or with an image maybe ?

A clearing operation, however, consists of raytracing through a grid from the origin of the sensor outwards for each observation reported.

Thank you !

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answered 2014-08-21 13:53:10 -0500

David Lu gravatar image

Sensor data gives you two things: Where an obstacle is and where an obstacle isn't. Imagine you have a single laser that starts at point A encounters an obstacle at point B.

The marking operation is putting a lethal value in the costmap at point B.

The clearing operation is taking all the points between A and B and marking them as free space.

The process of finding the line is often referred to as ray tracing, and is explained here:

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Asked: 2014-08-21 13:05:45 -0500

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Last updated: Aug 21 '14