

Faster pathfinding using Jump Point Search - harada
http://harablog.wordpress.com/2011/09/07/jump-point-search/

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praeclarum
"speeds up pathfinding on uniform-cost grid maps"

How useful are uniform-cost grids? Every implementation of A* I've ever used
has been applied to varying-cost grids.

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jemfinch
Any game vaguely resembling Wolfenstein uses a uniform-cost grid.

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pixcavator
What a strange use of the word "symmetric": "Two grid paths are symmetric if
they share the same start and end point and one can be derived from the other
by swapping the order of the constituent vectors."

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demallien
How so? That would be a 2-fold rotational symmetry, wouldn't it?

<http://en.wikipedia.org/wiki/Rotational_symmetry>

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pixcavator
Two pieces are rotated, that doesn't make the whole thing symmetric.

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wingerlang
Is it just me or does the Vanilla-A* algorithms look too bad? I mean
especailly in the second image [(d) A* (Adaptive Depth)], why does it search
behind itself?

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harada
This behaviour exists because A*'s heuristic function assumes there are no
obstacles when estimating the remaining distance to reach the goal. As the
difference between the heuristic estimate to the goal and the actual distance
increases, some nodes "behind" the start location will appear more promising
than other nodes which are eventually proven to be on the optimal path.

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sonar_un
Quick, someone send this to Toady One!

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malu
Problem is, the traffic designations make the grid non-uniform-cost. Edit: But
you could probably remove the possibility of traffic zones if this was
implemented.

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GoGlobal
Any speed ranking against alternatives?

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harada
In the paper we make an apples-to-apples comparison with a recent optimality-
preserving state-space reduction method called Swamps and an apples-to-oranges
comparison with an approximate pathfinding algorithm, HPA*.

Swamps is a nice technique for narrowing the scope of the current search; it
achieves ~5x maximum speedup and could be combined with Jump Point Search to
go faster still.

The comparison to HPA is summarised in the article. Additional evaluations are
the subject of further work :)

