说明：  This project is about implementing a world model that allows the path planning algorithm to query if a certain point in space is free from obstacles.
(Planning a path from one point of the environment to another while avoiding collisions with the environment is a complicated problem. As the number of degrees of freedom increases, the problem soon becomes very hard to solve. As computer power increases, probabilistic methods are being used more and more often to tackle these problems. This project deals with a method for path planning known as Probabilistic Road Maps. The basic idea with probablistic road maps is to randomly select a set of nodes/points in the environment that are free from collision and try to connect them with straight lines that are also free from collisions. A solution to the problem might then be found by finding a path through the graph from the start point to the end point. One of the key components in such an algorithm is the ability to check for collisions with the environment. )