Assignment A5

To execute our simulation the command is

./steersim –config Myconfig.xml –testcase testcasename –ai sfAI

The idea of this complex crowd simulation is combine social forces and A* path finder.

The idea of pathfinder work with social forces is put the sequence of nodes that generate by A* into the waypoint and goalqueue list, after reach the current local goal, set the current local goal to the next goal in the waypoint and goal queue list. Sometimes, the agent will crack when it reach the corner of obstacles, so we need to recompute the path in four way A*.

We merge the A* pathfinder into our social forces AI

In reset function push the sequence of node that compute by A* into waypoints and midtermpath and goalQueue list.

In the updateAI we use hasLineOfSightTo function to check is there any obstacles between the agent current position and the current local goal.  If there is an obstacles between the way to the local goal, recalculate the path with four way A* algorithm. in addition, if the local goal is to far away from the current position, it will also recalculate the path.

In most case the OBSTACLE_CLEARANCE = 0 In Maze testcase, the agent size is bigger than other testcase, so we increase the OBSTACLE_CLEARANCE = 2;

In A* we decide to choice weight to 2 and also chose big G value and Manhattan distance.

In the test case hallway-four-way-rounded-roundabout we have solve the polygon obstacles

Implementation method:

1. How to detect if polygon obstacle is in the agents' query area?

Using GJK to detect if agent. Position + query radius colloid with polygon obstacle. If so, we start to compute the repulsion force between polygon obstacle and agents. else, do nothing.

2. How to calculate the force between agents and polygon obstacle?

If polygon obstacle is in the query area of agents, first, we get the nearest vertices in the polygon and split the angel of this vertices in to two parts. Then we compare the vector from the vertices to agent and the vector from vertices to its next vertices to determine which side of the vertices the agent is. Then we treat the face of side of the polygon obstacle as wall to calculate the repulsion force.

In the office complex, we got segmentation fault. The reason is in this testcase the wide of obstacle is so small so many agent crack in the corner of the obstacles. So many recalculate path in this test case.

We increase the goal force time 4. So it can reduce the bounce between agents.

Our created test case is an airport simulation. Some plane are departing and some are arriving. And we also change the shape of agent and color. So it likes look UFO. 

wall squeeze CG Group 14
https://youtu.be/J2vI5Q-txbw

plane ingress CG Group 14
https://youtu.be/9qO_MUMFOpU

hallway four way rounded roundabout CG Group 14
https://youtu.be/fwh1C3knhEU

double squeeze CG Group 14
https://youtu.be/34lVXvQEG2k

airport CG Group 14
https://youtu.be/NdibtJ2kwZk

bottleneck squeeze CG Group 14
https://youtu.be/kbqUvrYE1rA

office complex CG Group 14
https://youtu.be/4iIxO_zA3ms

maze CG Group 14
https://youtu.be/yZ5s-hunnME

plane egress CG Group 14
https://youtu.be/75xuuXNNBmg

doorway two way CG Group 14
https://youtu.be/ZAhxFKZjubA

hallway two way CG Group 14
https://youtu.be/6xyE49ldB9w

crowd crossing CG Group 14
https://youtu.be/hiDJ5Dt19Bo