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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
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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)
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
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/RAI46be2S3E
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