1. Toward Solving Pathfinding
Kevin Dill
Chris Jurney
Alex Champandard

2. Why Isn’t It Solved Yet? Search is expensive Limited resources
Huge environments
Dynamic maps
Varied terrain & travel costs
Limited resources
Not everyone gets to work on the 360 or PS3
We still have to fight with the graphics guys…
* Ken Forbus story

3. Ok… Why Else Is It Hard? Incredible variety of requirements
Unit widths
Varied (and dynamic) formation sizes
Varied traversability
Dynamic obstacles (i.e. other actors)
Crowds
Tight spaces
* Uncle Steve story

4. Beyond Path Planning Believable motion Decision making
Soldier vs. tank vs. truck vs. … puppy?!!?
Unusual motion (jumping, gliding, flying, etc.)
Coordinating with animation
Decision making
Realistic distances
Screening forces
Traffic prediction
* Uncle Steve story

5. Optimizations & Other Tricks
Time slice (or multithread)
But what to do while you wait?
Hierarchical spatial representation
But what if the map changes?
My heuristic *was* admissible…
Precompute and/or cache results
Time / space considerations
Consistency

6. Toward Solving Pathfinding
Kevin Dill
Chris Jurney
Alex Champandard

7. BUILDING NAVIGATION DATA
Topic 1
BUILDING NAVIGATION DATA

8. Voxelization of Meshes
Most scalable and efficient solution yet!
Outperforms mesh simplification techniques.
Also very robust with clean output.
Example from Mikko Mononen’s R&D.

9. 3D Rasterization
Project by Mikko Mononen, 2009.

10. Area Contour Creation
Project by Mikko Mononen, 2009.

11. Triangulation
Project by Mikko Mononen, 2009.

12. Scaling Up
Project by Mikko Mononen, 2009.

13. PATH Following Diversity
Topic 2
PATH Following Diversity

14. Corridor Map
R. Geraerts et al., 2008.

15. References
Using the Corridor Map Method for Path Planning for a Large Number of Characters R. Geraerts, A. Kamphuis, I. Karamouzas, and M. Overmars. Proceedings of Motion in Games, 2008 Adding Variation to Path Planning I. Karamouza and M. Overmars. Computer Animation and Virtual Worlds Journal, 2008.

16. Ideas & Applications Corridor lanes, people travel on the right.
Shortest path vs. longest path preferences.
Varied path following with Perlin noise.

17. Corridor Map
R. Geraerts et al., 2008.

18. Strategic PATHFINDING
Topic 3
Strategic PATHFINDING

19. Potential Fields
J. Hagelbäck et al., 2008.

20. References
Using Multi-agent Potential Fields in Real-time Strategy Games J. Hagelbäck and S. Johansson Autonomous Agents and Multi-agent Systems, A Multiagent Potential Field-Based Bot for RTS Games Journal of Computer Games Technology, 2009.

21. Advantages Scalable to thousands of units. Emergent coordination.
Simple to implement.

22. Multiwinia

23. Toward Solving Pathfinding
Kevin Dill
Chris Jurney
Alex Champandard