* [Theta* & AP Theta*: ](http://idm-lab.org/bib/abstracts/papers/aaai07a.pdf) Theta*: Any-Angle Path Planning on Grids
* [Lazy Theta*: ](https://www.aaai.org/ocs/index.php/AAAI/AAAI10/paper/download/1930/1945) Lazy Theta*: Any-Angle Path Planning and Path Length Analysis in 3D