WIP: Auto-generate navmesh for brush ladders

[Rainyan]

Description

WIP, not ready for review.

Toolchain

• Windows MSVC VS2022

Linked Issues

• fixes #
• related #

[DESTROYGIRL]

Better than what I had in mind!

[Rainyan]

Better than what I had in mind!

To my understanding the ladders are omitted from the final world brush, so there's quite a lot of plumbing to retrieve them from the BSP brush lump which roughly corresponds to the geometry that Hammer sees. Although I'd love to be wrong, since that would simplify matters a lot.

Still some jank that needs cleaning up, like not generating ladders for un-climbable normals (up/down), and some angled ladders getting funny normals. But it kinda works! Hopefully I can clean it up to something mergeable for more convenient nav generation.

[Rainyan]

So the basic case works. Here's a ntre_dawn_ctg ladder with nav_generate_debug_brushladders debug. Green line marking a good side, orange too slim a side for bots to climb ("too slim" is arbitrarily chosen, they could climb them but it's hard to get good results in terms of the actual bot movement). And pink marks a side with insufficient clearance or inside a wall. Up and down facing sides are also removed from consideration.

There's some issues still with more exotic orientations that need fixing. This ladder "works", but obviously the rotation of the generated nav node is incorrect.

Also some interesting unintended routes which I would not probably have thought of manually adding, but are totally valid. This is an alternate climb path generated from the left side of the fence ladder:

[AdamTadeusz]

I don't have a map to check, can we climb upside down ladders in source? I know of at least one source game that lets you do that https://youtu.be/bbpG3iptMLE?si=GjWWkg2AiXMrovdX&t=749

[Rainyan]

I don't have a map to check, can we climb upside down ladders in source? I know of at least one source game that lets you do that https://youtu.be/bbpG3iptMLE?si=GjWWkg2AiXMrovdX&t=749

I will need to check but I think not. Would be kind of cool, although probably looks quite silly in third person without hand animations.

Up-facing ladders players can mount of course, and it's a mechanic for the ladder boosts etc. But it seems the bot ladder navigation system doesn't like that, so at least for now I'm choosing to skip those cases entirely.

[AdamTadeusz]

I don't have a map to check, can we climb upside down ladders in source? I know of at least one source game that lets you do that https://youtu.be/bbpG3iptMLE?si=GjWWkg2AiXMrovdX&t=749

I will need to check but I think not. Would be kind of cool, although probably looks quite silly in third person without hand animations.

Up-facing ladders players can mount of course, and it's a mechanic for the ladder boosts etc. But it seems the bot ladder navigation system doesn't like that, so at least for now I'm choosing to skip those cases entirely.

I think that's perfectly valid

[Rainyan]

I don't have a map to check, can we climb upside down ladders in source?

I am happy to confirm this is possible, and it's parity!

laddergoat.webm

[Rainyan]

Doing a cowboy rebase from browser since I don't have my dev setup at hand currently. But it should work fine as far as I can tell. If not, previous head 9165d79 should be known good but it doesn't have the convenient unity builds etc.

(Also pointing out there are memory bugs in this PR: particularly I could spot the polyhedron ptr being indirected after being freed. It's WIP code.)