A block line specifically for walking monsters (not player)

[Nirvana]

Since there's a block line for flying monsters specifically, it would be super useful (especially for something I'm working on right now!) to be able to block only walking monsters and allow flyers through. BLOCKF_CREATURES exists as a function but it is for blocking all walking monsters *including* the player and also it doesn't work properly (blocks flyers as well as everything else).

[Rachael]

Why do you want this? What is it you are hoping to accomplish?

[Nirvana]

Essentially it would just be useful in general to have a function that stopped walking monsters but not flyers, for a lot of different reasons:

1. Stop monsters falling off ledges making maps unmaxable, while still allowing flyers to pass over those ledges (also just line-blocking monsters on platforms so they don't get knocked off by rockets/BFG while allowing flyers to pass over these platforms)
2. Specific fight designs that rely on flyers being able to make it over packs off monsters that can potentially be blocked by these linedefs
3. For my specific case: helping walking monsters stay on patrol point paths while allowing flying monsters to pass over said monsters

I'm sure there are a number of other nuanced reasons why this would be useful, but these are the ones that come to mind.

EDIT: I should point out that I'm aware of hacky workarounds such as untextured holes in the ground to block monsters, but a proper method to do this in ACS would streamline mapping and be a useful function for a lot of other things.

[Bridgeburner56]

Having a block ground monsters only flag would be immensely useful. Just being able to wall off death pits to stop monsters getting shot into them while allowing the player to stumble in and have flyer go over makes this worth implementing. I know multiple mappers who have lamented this not being a feature after seeing that there is a block flyers flag.

[Matt]

I'm not a mapper but this suggestion seems eminently reasonable, like there's a conceptual gap that this fills in real nice.

As for use cases... one thing I can imagine is if the player's on a ledge with a railing that they can't go over, looking over a large area full of imps or whatever, and approaching from a distance is a bunch of lost souls. Left to their own devices the imps would keep approaching until they're right up to the ledge, where their fireballs can't reach the player. A ground-monster-only line would be perfect to keep the imps in a useful range while the lost souls start closing in...

[Megablast]

I'd just like to chime in that I would also find ground monster blocking linedefs useful.

Just one of those things where sometimes you just really need to place some impassible lines to direct ground traffic or block off cliffs you don't want the player to rocket thrust monsters off of.. Without having your air monsters getting stuck on all sorts of invisible walls. Afaik no ports support this feature.

[Enjay]

Yes, over the years, I too have found many situations, similar to those described, where a "block walkers" flag would have been useful. The advice that I was given a long time ago was to use the "invisible trench" method (hacky work around mentioned by Nirvana) but a proper line flag would be so much better and so much more flexible.

[Rachael]

Just posting to say this is on my to-do list, I dunno when I'll get around to it but I definitely plan on it. It doesn't seem to be too hard to do.