Pathfinding and ledges

[nick.ace]

I'm running into a problem with pathfinding where you have a ledge like this:

 

<- enemy

-----------

player |

----------------

 

The problem is that if the ledge is big enough, a path can't be created (which makes sense). However, GoToPoint still returns true (presumably because the point that the enemy is trying to go to is on an unconnected navmesh).

 

Anyway, all I need is for the enemy to be able to walk over the ledge. How would I recognize that the enemy reached the edge of the upper platform though?

[gamecreator]

The recognition is the easy part. I would use Pick from the tip of the feet to some distance directly below them. If the collision is far enough away from the foot (or if there's no collision) then the character is standing on a ledge.

[nick.ace]

Aw, good point! Never thought of doing that! Thanks!

[Einlander]

You should read this. http://www.valvesoftware.com/publications/2009/ai_systems_of_l4d_mike_booth.pdf

 

It has some AMAZING insight for Ai and pathfinding. As soon as I finish my fps controller, I plan on adding the climbing features and a secondary nav system to help them navigate ladders and ledges

[nick.ace]

Thanks! I actually saw those slides and a few others from Valve a few years back. I'm amazed at the number of picks that they perform with the number of zombies that they have and are still able to get good performance.

 

My AI has a similar thing going on (the parkour example in the Workshop uses a similar method) to get over edges.