WORLD NAVIGATION

FROM OUR MINDS TO YOURS:

A Lecture by Shift Our Bits

Don’t Fall Asleep Through These Topics

Tile Graphs Points of Visibility NavMesh Path Smoothing Hierarchical Pathfinding

Tile Graphs

Large and sometimes complex environments based on squares or hexes

Each node represents center of the cell Graph edges are connections between the adjacent cells Primarily used in RTS and war games Mainly used for games maneuvering across terrains Algorithms use this information to avoid water, mud, and hills Downside is the graph gets too large too fast.

Points of Visibility

A navigation graph that each node has line of sight to at least one another

The graph nodes will connect all important areas in the world Nodes can easily represent good sniping, cover, or ambush

positions Good for small maps

Downsides: Problematic over large and complex maps Problematic with any type of map generation feature

(must develop some automated method to generate POV)

Points of Visibility Graph

NavMesh

A network of convex polygons that describe the walkable areas of the game environment

Property allows unobstructed travel from any point to another Data structure is compact and can be searched very quickly Good for 3D FPS games because environments is constructed entirely

from polygons Possible to use algorithms to partition the walkable areas of the maps

automatically

WORLD OF WARCRAFT HAND CHECK

Path Smoothing Paths in grid shaped graphs usually have unnecessary

edges Looks unnatural to human eye because of the kinkiness Smoothing is obtained from using A* and distance heuristics A quick method for smoothing a path works by checking the

“passability” between adjacent edges http://youtu.be/RA

I46be2S3E

Path Smoothing

Path Smoothing

Hierarchical Pathfinding Similar to how humans move around in their environment Two levels One level is the path is planned using a series of areas (IE:

dining room, kitchen) The lower level is planned using a series of points through

those areas

You can stop pretending to pay attention now.