OpenFLANN

I found PicoFLANN and compare the speed of alorithms, namely PCL FLANN, NanoFLANN, and PicoFLANN.

Characteristics

• Set NanoFLANN and PicoFLANN to be avaiable on Point Cloud Libarary (PCL).
• It's simple to use them! Just git pull this repository, then copy & paste the header files in include folder.
• Usage is totally same with Point Cloud Library, i.e., setInputCloud, nearestSearch, or radiusSearch.
• Many robotics guys refer to NanoFLANN in LOAM; however, the function radiusSearch in LOAM is actually not in use so the function does not work properly. So, I debugged it and revise the radiusSearch.

Reference

• PCL FLANN
• NanoFLANN
• PicoFLANN (The original developer says it is faster than NanoFLANN, and it actually is when the scale of points becomes larger)

Simulation results

Experiments: Please refer to src/main.cpp. I reran the experiment 1,000 times to measure mean speed of each case.

One-line summary: For robotics application, NanoFLANN is better than other FLANN implementations.

You can show the results via python code (tabulate is necessary)

cd outputs
python viz_output.py

K-Nearest Neighbor

Radius Search