[BUG] Lost souls get stuck in the air vents

[kianzarrin]

GZDoom version

GZDoom 4.14.2

Which game are you running with GZDoom?

None

What Operating System are you using?

Windows 11

Please describe your specific OS version

No response

Relevant hardware info

No response

Have you checked that no other similar issue already exists?

• I have searched and not found similar issues.

A clear and concise description of what the bug is.

In TNT map 18 in the final area, sometimes the lost souls (or even Cacos) get stuck when trying to come down the vent.
If you move the other side of the air vent, it helps the lost soul to get unstuck

In the video below I can see the lost soul is trying to go forward and down at the same time but it can not go in any direction (lost soul's movedir was north when I debugged it):
https://github.com/user-attachments/assets/4df6dc08-c3b6-4774-8d59-83ac31634953

Importance: In my play style (I pick up invisibility and wait there for infighting) I frequently encounter this bug because I don't move around.

I am not familiar with doom but if I am not mistaken this is my explanation:

• the demon is trying to go down but it collides with floor and bounces back up
• the demon cannot get over the edge of the floor because there is a wall in front of it.
• normally when demon hits a wall it changes direction but here because it is not only trying to go forward but also is trying to go down it does not change direction.
• if my analysis above is correct to fix this the lost soul to change direction when hitting the wall even when it is trying to go down.

Steps to reproduce the behaviour.

1. in TNT Map 18 (mill) in the final area you need to shoot a wall to open the air vents. stand in front of the wall and shoot it to open the air vents
2. wait and DO NOT MOVE: Sometimes (maybe 50% chance) Lost souls or Cacos get stuck in the air vents and they will never come out. you can verify this in the map using IDDT to show demons.
3. if you move to the other side of the vent the lost souls get unstuck

Your configuration

I managed to reproduce this both in `default` compatibility mode and in `boom` compatibility mode.

Provide a Log

No response

[kianzarrin]

Which part of the code is responsible for handling going forward and down at the same time (going over the edge) which prevents changing direction when lost soul hits the side wall (if that is what is happening)?

[RicardoLuis0]

is this an engine bug, or just a mapping bug? if it's a mapping bug, and still happens even in vanilla engines (ex. chocolate doom) then there's not much gzdoom can do about it

[drfrag666]

Wenas. But this is the gzdoom repo not uzdoom's xD

[pyropeta]

Wenas. But this is the gzdoom repo not uzdoom's xD

This is off-topic, but oh, I don't know, maybe it's cause they didn't intend to post this to UZDoom's repo??? Plus, AFAIK, GZDoom hasn't stopped development. There's still gonna be updates even though UZDoom will be the one most people flock to, most likely.

[drfrag666]

No, Jay was the one who mentioned UZDoom but then edited the message. Probably she confused the repos. Y wenas.

[pyropeta]

No, Jay was the one who mentioned UZDoom but then edited the message. Probably she confused the repos. Y wenas.

Ok, that makes sense. Sorry.