15 replies to this topic

[xiongyouyi]

Does starcraft2 use navmesh A* or grid A* for pathfinding?

[IADaveMark]

It uses a navmesh. Also please note that there is a bunch of steering code happening in there rather than simple A*.

If you want to see slides from James Anhalt's GDC presentation on SC2 pathfinding (and have some time to wait for a long PPT download), you can get them from here.

http://gameai.com/papers.php?a=23&t=&e=&y=

[japro]

Does the download work for anyone? I now downloaded it three times (two times on my windows machine and once on linux) but the zip seems to be broken .

[Mihai Moldovan]

Your question doesn't make sense.

A* is an algorithm while a Navmesh is the data structure (graph) representing your terrain. Thus SC2 uses both, A* and a Navmesh, and steering behaviour on top of that.

Anyway, I wouldn't try to learn from what Blizzard is doing with their games. They're really just not that good except for their marketing and cinematics team.

Edited by Mihai Moldovan, 30 April 2012 - 05:59 PM.

[Cornstalks]

Your question doesn't make sense.

A* is an algorithm while a Navmesh is the data structure (graph) representing your terrain.

His question makes perfect sense. He was wondering if A* was used on a *navmesh* or on a *grid*.

Anyway, I wouldn't try to learn from what Blizzard is doing with their games. They're really just not that good except for their marketing and cinematics team.

Wow... Ok...

[IADaveMark]

Your question doesn't make sense.

A* is an algorithm while a Navmesh is the data structure (graph) representing your terrain. Thus SC2 uses both, A* and a Navmesh, and steering behaviour on top of that.

Anyway, I wouldn't try to learn from what Blizzard is doing with their games. They're really just not that good except for their marketing and cinematics team.

You went 0-2 on this post.

1) Read the person's post before you bust out the snark.
2) You are knocking arguably one of the best game design teams in the history of ever.

[xiongyouyi]

It uses a navmesh. Also please note that there is a bunch of steering code happening in there rather than simple A*.

If you want to see slides from James Anhalt's GDC presentation on SC2 pathfinding (and have some time to wait for a long PPT download), you can get them from here.

http://gameai.com/pa...p?a=23&t=&e=&y=

The ppt zip is broken, I cann't open it.

[IADaveMark]

Sigh. That's the one hosted on the GDC Vault site. Let me see if I have my own copy around here someplace.

[Okay Lin]

Sigh. That's the one hosted on the GDC Vault site. Let me see if I have my own copy around here someplace.

Could you sent me the "James Anhalt's GDC presentation on SC2 pathfinding", thank you very much
email flin0529@gmail.com

[IADaveMark]

That's the one I linked to. The SC2 portion is only about 20 minutes. The rest of the hour was stuff from 2 other games.

[web383]

I'm also interested in the SC2 presentation if anyone has a valid link or copy.

[japro]

I'd also be very interested.

[Indakung]

I found that the buildings in SC2 are on grids, it seems like they combined both grid and navmesh?

I cannot open the zip too, could anybody help?

Edited by Indakung, 08 May 2012 - 07:34 PM.

[xiongyouyi]

I found that the buildings in SC2 are on grids, it seems like they combined both grid and navmesh?

I cannot open the zip too, could anybody help?

I guess, the navmesh is used for pathfinding, the grid is used for placing building, generating terrain, calculating neighbors in steering behavior

[Indakung]

I downloaded SC2, and tried its editor. Press Ctrl + Alt + H to show navMesh and put some buildings on it, it shows the dynamic generation of navMesh for the building's constructions and destructions clearly. Or you can also add polygon directly.

It's Delaunay algorithm isn't it? But my question's still: how to deal with agents in different sizes? The editor doesn't shows if it generated various layers for different size of agents.

Edited by Indakung, 08 May 2012 - 10:51 PM.

[IADaveMark]

Yeah, I was going to say that the grid is just for building placement. It just gens the navmesh as needed. That's a well-documented approach for navmeshes and changeable terrain.

I looked through my AI summit files from last year and didn't see a copy of James' slides. I will ask him if he has them sitting around.

To be honest, though, the slides aren't going to tell you much.