Need help with DYNAMIC_RRT_2D

[minhduc66532]

I'm doing some stuff that dynamic rrt 2D will fit perfectly. But I'm having a really hard time understand the code. I know the basics of RRT and RRT* but the code still confusing.

1. Why separate Node and Edge ? You can just create a Node with a parent node and a child node right ? And in Edge class parent and child is a Node ?
2. How do you represent the entire map ? Using some kind of grid ? And can you show me the code of that grid ?
3. What's the difference between generate_random_node and generate_random_node_replanning ?
4. What does the is_collision_obs_add function do ?
5. What is self.utils.delta value ?
6. What do extract_path and extract_waypoint function do ?
7. In the DynamicRrt class what is
   - goal_sample_rate
   - waypoint_sample_rate
   - iter_max
   - vertex
   - vertex_old
   - vertex_new
   - x_range
   - y_range
   - path waypoint
   Thank you