Rather than just disregarding it for existing levels, could they be padded / shrunk accordingly?

The next version of RetroLemmini (most likely 3.1) will no longer support variable level boundaries.

It's currently possible to set the boundaries to anything, but the default values are the only ones that actually make sense, at least from an engine maintenance point of view. Allowing them to be set to anything (particularly the top boundary, the physics for which is notoriously difficult to perfect) just causes unnecessary problems.

Furthermore, whilst variable boundaries might be a fun thing to experiment with, it's unlikely to produce any particularly good levels.

So, let's go ahead and set these values to defaults program-wide. Then, I can address the top-of-level physics properly and make sure there isn't anything unintended happening.

This topic is to provide users, creators and maintainers with an opportunity to voice any concerns or add to the discussion at this stage, before the next version is released.

Your silence = this will go ahead as planned, any levels affected by this change will be disregarded.

This bug has brought about the question of whether levels should be able to mess with the level boundaries. Personally, I see no good reason to allow this. It's most likely a hangover from support for some early level format or something, i.e. it seems unlikely to be a desired and intentional physics feature.

I'm tempted to strip variable level boundaries out of the code (the Editor doesn't support it directly anyway), and maintain the default boundaries for all levels. This will make it much easier to then tighten up top-of-level physics.

As it stands for now, I've gone ahead and committed the Builder fix (i.e. Builders now always stop building at Y=8, making it practically impossible for a lemming to reach Y<8), but will soon come back to the top-of-level stuff later, likely in a separate topic.

This one can be considered resolved, then.

Fixed in RLPlayer commit f142f69.

Confirmed.

This is happening because of a clash between these physics rules:

1a) The level must specify a top boundary of 0 or greater, with 8 being the default if none is specified
1b) In the level provided by hrb264 (attached here), the boundary is set to 0, so lems can build all the way to the top of the level
2) If a builder lemming is at or above the top boundary (usually 8, but 0 in this case), they will stop building
3) If a lemming encounters an obstacle that is too tall for them to step onto or their y-position is less than or equal to 8, they turn around - the latter of these conditions is symptomatic, which is the source of this bug

The first and foremost fix is to stop lemmings from building when they reach the default top position. This is easy, and fixes hrb264's example level/replay.

Preventing lemmings from repeatedly turning (which is what traps them at the top of the level if they reach a certain height) is harder: what should the condition be, and how can we make sure the fix doesn't create side effect bugs of its own?

It's too hot to think about this right now. I'll come back to it later.

---

P.S. I've also attached a level (Top of Level Test) which makes it possible to reproduce the bug:

1) Allow 1 lemming to walk up the stairs (contain the others with Blockers). They will turn around before reaching the thin platform and begin to walk back down the stairs
2) From the stairs, have them build up to the platform. The platform will stop them, they will turn around, step into the thin platform, and continuously turn around

If we can prevent this, the bug will be fixed for all levels, regardless of any other factors.

Despite being certainly a step up in terms of difficulty, the Tense-rank was not a hard as I thought - with one notable exception. My favourite levels ware Tense 1, Tense 8 and Tense 9.

Spoiler

Panic

1 - Help is on the way!

Repeat of Tense 7 and much easier than that. I think both levels should be swapped. This here is what came immediately in my mind when I first saw this level.

2 - Lemming-lime soda

I thought about the bottom route pretty early, but didn't think I could make it past the bucket without using a terrain-removing skill. So I was a bit surprised that the Lemmings easily walked over the handle. Which solved the level.

3 - Tension

Another repat and a very good level. It's a bit of a playground with multiple solutions possible I assume. I had lots of skills left here.

4 - Freezer Burn

From hot to cold. The steam blower kills all the Lemmings from the upper entrance instantly, so one from the other hatch has to save them by building a bridge. This is not so easy as it requires some devious tricks such as interrupting a basher midstroke to gain height. Interesting however, that the pioneer is able to walk just beneath the steam blower without getting hit.

5 - The Serpent

This one is all about squeezing the crowd together as much as possible. I assigned three climbers to bring one through the trap. The rest is pretty standard.

6 - Lemming Replacement Therapy

Hard and pretty annoying level. Key was when I found out that three Miners at the bottom were enough (not four what I had thought before). This allowed me to make one more Lemming a miner at the start and delayed this particular Lemming - which was crucial.

All my solutions can be found here: https://www.youtube.com/@Swerdis

lemming movement test

Hi Nessy! Great to see you back, and nice to meet to meet you! Gotta say, I really enjoyed playing through Destination, and Migration, both excellent packs!

So im starting on a game called lemmoria, its less ambitious than my other projects but i mean like
uhhh
 
its about playing as a lemming in some sort of endless building to try and get to the bottom, its a realistic survival game that will have MANY health mechanics.
so anyway i wanted to share my progress. i made the head for the lemming as the game will use dynamic layers to show the lemming you play as

Hey everyone!!

Wooow, it's been a while LOL. I'm honestly over the moon that people are still playing my stuff to this day and enjoying it Thank you all for the replays, feedback, and kind words! I definitely need to take some time to get up-to-date on everything and go through all of this, but it'll be fun to revisit Destination because I honestly don't remember some of the solutions I came up with back then haha

The solutions for my levels are intended! Great job!