Killing Floor Pathing Tutorial  (Read 3738 times)


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Killing Floor Pathing Tutorial
« on: March 05, 2010, 17:45 »
KF path mapping was very poor.  I don't think anyone on the old mod ever read an Unrealed pathing document, and TWI map pathing isn't any better.  I just a played a new ported map for the community patch and the pathing was so bad, my mother cried.

(edit: I just noticed the post has a slider bar at the bottom so you can see the whole of the pics)

Before we continue, remember, if you change anything on your paths: do a FULL path rebuild.

How to see your paths

Pathing between a wall and an object.  Place a node in the place where the zombies go thru - then make there is a STRAIGHT way to it - and maybe a STRAIGHT way out.  Required width is covered below using an FP as a measure.  And also the alternative using a "forced path" or jumpspot.


The "forced path" or "jumpspot" in the distance on the ground.
Do not presume because you have a path line *from > to* that it is good path.  In the pics there are many path lines from roof to ground, but the zombies rarely if ever use them and jump.  The jumpspot is the "forced path."  A forced path means: you CAN go this way (not: you are forced to go this way).  It tells the zombie AI - this path looks impossible but it IS possible - IF you want to go that way.

How to make a "forced path"  pathnode > to jumpspot (jumpspot is a forced path, lest you forget)

You can use jumpspots anywhere - not only to tell them jumping down or up is ok.  I use the jumpspot (or forced path) on either side of standard unreal mover doors.  A jumpspot either side of the standard unreal mover door - each 'jumpspot' has the object name of the other in its navigation > 'forced path' section.
In Horztal at the facility entrance behind the taxi, the wire door there are two jumpspots - that's why the FPs keep pushing at the wire door.  They can't get thru until the taxi is blown.  But I needed the 2 'forced paths' because otherwise the path builder would not have built a path.


  The zombies would not go out this window before I placed a forced path or jumpSpot there.  Again forced path or jumpspot means - "this way looks impossible, but it is possible - IF you want to go that way."

If you don't want zombies to follow a path, use the navigation point > proscribed path.  That creates a red path line.  It doesn't work that well if you have a lot of paths in that area.  Because if you make a path proscribed, the path builder usually picks up on a more distant node and adds another path, and the proscribed like 'forced' only has 4 slots.


Obviously use the fewest pathnodes possible.  Because the more pathnodes, the more the AI has to think, so using more CPU power.


The jumpspot is used wherever zombies have problems getting to, or past, or over, or down, or around.  If the mfs are having problems or looking confused use a forced path (jumpspot).  Seems tinypic cut off some of the pic.  But it says: the forced path tells him, even if he can't fit, he can go thru.  And if you've ever tried to glitch on HappyHour roof you will know that FPs can get you there.

Rather than using 'forced paths' all the time, use an FP to make sure your doors and paths are wide enough.  If he can fit, everything can fit.
Also notice the pathnode placing on all of the pics - they go wide around corners.  The reason is so zombies avoid bumping into corners.  Same as the pathnode placement through KF doors - place pathnodes so paths goes through the middle.  Be nice if zombies came around corners more naturally, but they don't.  You will have seen them getting stuck on corners.  Now you know why that happens.

Make sure there are paths going through your zombie spawn volumes so the zombies don't have have to waste CPU power figuring the location of their nearest path.

Remember, if you change anything on your paths: do a FULL pathing rebuild before you run the map or the zombies will just wander aimlessly.  "Build only changed" pathing is just so you can figure a small pathing area - and it just builds that changed area but removes all other paths, so after using that option you need a full path rebuild anyway.

Colour coded path lines - well white means it's like a zombie highway.
Blue similar to green - but blue means narrower paths.
Yellow - the "forced" path
Red     - the proscribed (forbidden path)

Hope that's helpful.
And even if you think you're a crap mapper, BoxWithoutHope must be the crappest map ever made, but it is brilliant to play ^^


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    • rajliv
Re: Killing Floor Pathing Tutorial
« Reply #1 on: March 07, 2010, 09:01 »
nice tut...


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Re: Killing Floor Pathing Tutorial
« Reply #2 on: April 19, 2015, 19:44 »
A monster will find a player within 1200uu of a pathnode.

The pathnodes in the first pic are about 500uu or less apart.  That means there are too many pathnodes.  It will take longer to rebuild the pathing.  And in-game it will take longer for the AI to calculate a route to the player.

The second screenie is the same path area as the first screenie re-done with a satisfactory quantity of pathnodes, about 3.  Pathnodes don't need to be place on inside corners - as long as there's a pathnode within 1200, the monster will find them - also known as: the monster will see them.