Yandros on 14/1/2005 at 18:23

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I'm sure there's a legitimate property you can set on the objects, because AI can walk on the catwalks (like in Shipping... And Receiving). So somebody will no doubt come along and tell you what to do.

But one way to get around it is to create solid brushes where your objects are, compute pathfinding, then delete the brushes and reportalize (but don't recompute pathfinding). However, that means you have to do this right before releasing your mission because if you ever compute pathfinding again without the brushes there, the AI will lose the ability to walk on the objects.

I should also say this is complete hypothesizing on my part, I haven't actually tested it. But I think it will work.

PinkDot on 14/1/2005 at 22:45

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AI can walk on that objects but only on the first floor (it's kind of wooden scaffolding). The second floor is made of the same objects as the first floor. So I wonder if AI just cannot go higher starting from OBB to another OBB? (normally he goes from solid ground floor onto OBB)

I gave my objects properties:
- pathable object - to let them walk on it
- path avoid: block the pathfind - to avoid AI walk through the diagonal plank
There is also Path Exact OBB - is there anyone who knows what does it mean?

EDIT:
Yandros: your idea sounds intersting but as my architecture is almost too complicated now I'm afraid Dromed could not handle any more brushes... :( But I'll try it if every other solutions would fail...

I'm experimenting with scaling objects and now I know that there is possibility to walk up from one OBB object to another but it probably depends on the dimension of the objects. I/m going back to experimenting...!

vfig on 11/10/2023 at 16:30

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thank you, i needed to know this today.

my semicircular catwalk was generating overlapping cells (a bad thing), and not generating any links between them. to resolve this, i changed to AI>Utility>Pathable Object false on all the visible catwalk objects, and added invisible objects with AI>Utility>Pathable Object true, that are all nicely axis-aligned and lining up against each others edges.

(https://imgur.com/a/TwUM90j) https://i.imgur.com/X0sIsva.png

i still had an issue with one path link not connecting correctly between the two OBBs: you can see how the link goes to the edge of one cell, but is not connected in the next cell. i havent figured out why yet. but moving one of the pathable OBBs up by 0.25 units resolved it:

(https://imgur.com/a/TwUM90j) https://i.imgur.com/PekumRX.png

update: turned out my broken link was probably a result of there being terrain close below the OBB object. once i adjusted the terrain so there wasnt walkable terrain close under the catwalks, the broken link went away entirely.

also:



i dont believe this is correct. i see the pathfinding building cells that match the OBB dimension regardless of whether i have updated the model scale to match (for visual convenience).

R Soul on 27/12/2023 at 21:42

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I'm glad you posted this because I've been trying to use pathable objects in my cave/mountain system and was not having much success. Now I realise it's becuase very few of my terrain edges are parallel to the XYZ axes, so my objects can't line up properly.

In one place I have a steep set of 'steps' (or ledges forming a steep stair-like structure) which the player can drop down or mantle up. There are plenty of ways for the AI to navigate via other paths, but I wanted to use pathable objects to allow an AI follow the player.

Terrain:
http://catmanofiowa.com/RSoul/img/cavesteps1.jpg

Steps visible:
http://catmanofiowa.com/RSoul/img/cavesteps2.jpg

As you can see the path links are a bit messy but AI navigation works. Each step needs to be properly lined up in the Top view with the one before and the one after (as seen in vfig's screenshot). Although I'd like to provide a definitive limit on the maximum step hight you can use, the complexity of this terrain is leading to results that are hard to predict. I tried again in a simple area and it looks like the limit is around 2 feet.

Steps can overlap in the top view if they're not directly connected, e.g the three marked with white stars:
http://catmanofiowa.com/RSoul/img/cavesteps3.jpg
This would also allow for a squared-spiral set of steps. For the above path, the steps are so tightly arranged that it's also necessary to disable the property Physics > Misc > AI Collides with, otherwise the AI's phys model causes it to get stuck. The AI type also helps. Elementals find it easier as they're smaller than humans, but the step height is still important.

R Soul on 28/12/2023 at 02:52

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Thanks for the tip. I'll implement that. Also after some further testing I found that the AI was fine descending, but not ascending. When reducing the step height to 1, the AI could ascend again. Either the step height limit is approximately 1 or the phys models do need to connect vertically.

Edit: the step height should be quite a bit less than 2. The limit is probably closer to 1. It can descend 2 but ascending is too hard; the AI tends to get stuck. I also experienced similar problems to vfig with some terrain directly under the objects being too close. The AI seems to have trouble knowing which path to take.

I've decided that for this terrain setup it's not worth putting in the effort to make objects work. I'll revert to the old way of using additonal terrain when pathfinding is being done and then moving it out of the way for the final build:
http://catmanofiowa.com/RSoul/img/caveslope1.jpg