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Newcomers DBPro Corner / a question of A* performance

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Olympic
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Joined: 18th Aug 2004
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Posted: 4th Sep 2004 07:26 Edited at: 4th Sep 2004 10:01
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I implemented A* by DBc which based on waypoints system
so finally there are about 30 nodes(waypoints) in the map.

The A* function only cost 0.365ms to find a path
I am searching articles to find the tendency that with the number of searched nodes increasing how much the time consumption will be increased?

say 30 searched nodes(waypoints) will take 0.365ms, how about 300 searched nodes? and How many nodes(waypoints) are normally placed in a real game? (like quake?)

Is there any articles talk about the relation between time consumption and the number of searched nodes in search algorithm?

Thanks a lot!
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Phaelax
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Joined: 16th Apr 2003
Location: Metropia
Posted: 4th Sep 2004 11:14
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The time is going to depend a lot more on how much of your map contains obstacles. A completely empty map will find a path immediately. See where I'm going with this?
Because of the obstacle variable, it's probably why I couldn't find a time function showing how long it takes to find a path.

"eureka" - Archimedes
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Arkheii
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Joined: 15th Jun 2003
Location: QC, Philippines
Posted: 4th Sep 2004 11:40 Edited at: 4th Sep 2004 11:44
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Quake is fast because it only does a path search every tenth of a second.

Quote: "The A* function only cost 0.365ms to find a path"


Too slow, that's a third of a second! Unless it is intended for something with less intense gameplay, that will affect your framerate.

http://www.aiguru.com/pathfinding.htm

Take a look at the two-tiered pathfinding article.

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eat much pie
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Joined: 9th Apr 2004
Location: Within the mind of a lowly mortal...
Posted: 4th Sep 2004 23:00
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I'm making a checkpoint routing program for this exact problem. It has quite a bit more functionality than A* and is very easy to use. See my website for more info and a beta demo:

http://eatmuchpie.dbspot.com


[href]Checkpoint Router[/href]: My AI Routing Program
Sam Wright
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22
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Joined: 27th Aug 2002
Location: United Kingdom
Posted: 5th Sep 2004 04:15
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too slow?, he might mean one third of a millisecond, that wouldn`t be too bad and probably explains why he said only, even my "big dumb pathfinder" could do a four hundred nodes in under 1m/sec back when the fastest machine I had was 1.2ghz.

Mentor.

PC1: P4 3ghz, 1gig mem, 2x160gig hd`s, Radeon 9800pro w cooler (3rd gfx card), 6 way speakers.
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Arkheii
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Location: QC, Philippines
Posted: 5th Sep 2004 22:24
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Oh. I thought it was 1/3 of a second. My mistake.

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