Quote:
|
1. There is no way to visualize them in the client, so no way to really see what your doing.
|
While it might not be the cleanest and most efficient way to place nodes, I do believe it can be adequately done through the client. Say for example that you want to place a node. You stand at the spot you want the node to be placed, and use some kind of #addnode command. The #addnode not only records the loc of the node you placed, but also spawns a skeleton at that exact loc. When you move onto the next place that you want to add a node, you can then look back and target the previous spawned skeleton and type #LOSnode which will check your current LOS @ 5 feet above the ground to 5 feet above the ground where the skeleton is (nodes shouldn't be locked to the ground but at eye level as you suggested). If you want to delete a node, just target the spawned skeleton and type #deletenode, which will check the loc of the targeted skeleton and reference the node also at that exact loc, and delete it. Though you'll never be able to physically see the connections being drawn, this should be decent enough to lay down nodes and do some testing to see how AI would behave under these conditions.
Note that I don't feel that this special pathing is necessary in large outdoor zones since its mostly just flat land anyway, and little to no walls to have to navigate around. Hell, on EQlive this pathing doesn't take place either, as I fondly remember hunting in Qeynos hills and having monsters agro on me, and try to run through the walls of the little cottage there. This node pathing should only really be necessary in dungeons and cities where there are a lot of thick zone geometry that needs to be intelligently navigated as to prevent a mob from walking through walls or falling through the floor and cause trains. Limiting the construction of nodes to only dungeons and cities. it probably won't be as difficult or lengthy a job as you might think.
The reason i brought this node system up is because I've done a bit of work in the past building levels in Unreal, monster AI there used a very similar system of laying node nodes which allowed mobs to navigate the level with great precision. Though i'd love to get a look at the AI code in Unreal to see how it works, I don't think that is available. I've found a bit of text from the old unreal technology site, which might give a bit of insight as to how their AI worked.
Code:
PathNode placement
You can place pathnodes manually, or you can use PATHS BUILD LOWOPT from the console to get a first pass placement done automatically. In any case, you must do a PATHS DEFINE from the console to create the connections between pathnodes.
To use the navigation system, a creature must first choose the best nearby node to "get on" the network. For performance reasons, creatures limit their search for path nodes to those within an 800 unit radius (see FSortedPathList::FindVisiblePaths in UnRoute.cpp). This is because the test to determine if a creature can reach a path is very expensive. However, once creatures are "on the network", travelling from pathnode to pathnode, they use the reachspec tables in each pathnode to determine reachable nodes. There is no distance limit for reachspecs, so paths may be defined between two pathnodes which are any arbitrary distance apart. For performance reasons, paths between distant pathnodes which have a suitable alternate
path using intermediate path nodes (with a low added cost) are culled from the path network.
I recommend that paths should be less than 700 units apart, so that creatures don't ever start off going in the wrong direction to get on the network. In addition, paths on stairs and ramps should be closer together (<350 apart) Given that, you should use the minimum number of paths needed to cover the area for which you want intelligent navigation. Note that all navigation points are equally used as paths, so there is no need to place pathnodes redundantly near patrolpoints, etc..
Paths should in general be placed at intersections, making sure that they have the maximum visibility in all potential directions. Paths need a line of sight to each other, clear to the width of the maximum width (2 * collisionradius) of creatures which will use this path. You should also place paths on ledges, with a line of sight to paths below, so that creatures can intelligently navigate jumping off ledgest. Vertical line of sight has no extent requirement.