NeoLemmix > Closed

[BUG][Player] Step-up through an 8 pixel steel ceiling possible with stacker

(1/2) > >>

IchoTolot:
I found the following:

When you have an 8 pixel steel ceiling it should be impossible to step through it.

Now in the attached test level you have a ground floor 4 pixel under said steel ceiling.

The stacker is placed in a location that is timed perfectly so that a lemming that steps up (I think from the right) becomes weirdly stuck inside the ceiling way higher as he should be and as a result stepping up through it.

I don't know exactly what goes wrong here though, but it should be a bug 100%. ???

namida:
Haven't had a chance to watch it yet, but from the description I can both guess why it happens and confirm it's a bug - it's (I suspect) basically a far more limited form of L1's sliding glitch, and could likely also be pulled off in a similar fashion with a 1px notch just below the ceiling.

namida:
Modified version of your test level that only has 2 lemmings with a precisely-timed RR, rather than a constant RR99 stream. This makes it easier to see what's going on. Beyond creating this variation (and confirming I can reproduce it), haven't looked into the cause yet.

namida:
Okay so looking at this - this is a really tricky situation that I don't know if there's any good answer to "what should happen?".

Here's what happens:

1. Lemming A turns around at the wall and immediately is assigned a Stacker.

2. Lemming B steps up and walks over the incomplete stack, and turns around at the wall.

3. Lemming B encounters the stack, at this point 3 pixels tall, and begins to ascend.

4. As Lemming B is ascending, Lemming A places the 4th brick, sealing the gap between the ground and the wall above.

5. Lemming B continues to ascend. Because ascenders don't check for overhangs (only for a gap, or for reaching the 6px maximum ascend distance), he continues to ascend until he has ascended a total of 6 pixels.

6. Lemming B turns around and becomes a faller, as is the behavior for a lemming that ascends 6 pixels without encountering a gap where he can become a walker.

7. Lemming B immediately detects terrain below him (as he's 1px inside the overhang) so becomes a walker.

8. Lemming B has >6 pixels in front of him so cannot ascend, so turns around.

9. Lemming B has exactly 6 pixels in front of him so can ascend, and does so.

This would also confirm my theory that you could do it similarly with other skills + a small nook; but somewhat disproves the comparison to sliding - the lemming is not ascending further than he otherwise should be able to; it's just a very specific setup where he manages to ascend into an awkward spot, from which he can ascend a second time, to ultimately still only clear the normal distance expected from two ascends - 12 pixels.

IchoTolot:
I think get the behavior.

Normally I thought it was a rule that a lemming can step through a thin ceiling. In reality it is just a general example of the ascending behavior:

- A lemming walking through a 1 pixel line of empty space can step up through a thin ceiling. The step up can be up to 6 pixels and as he still needs to ascend through the empty space the ceiling can't be 6 pixels.

Here we have the extreme case that a lemming is already inside terrain and steps up 6 pixels again.  Especially he having 6 pixels of solid (steel) terrain above (not infront of) him is the counterintuitive thing .

If there is a problem to solve it would be this part maybe - the way he initially already gets 2 pixels inside the ceiling and later just going through 6 solid terrain pixels above him - by just ignoring all overhangs while ascending:


--- Quote ---5. Lemming B continues to ascend. Because ascenders don't check for overhangs (only for a gap, or for reaching the 6px maximum ascend distance), he continues to ascend until he has ascended a total of 6 pixels.
--- End quote ---

I think this could be a very far reaching physics change though as it would affect general common behavior and maybe is another case of "things new engines will need to think about".

At least, I would advocate for a "please do not rely on this!" warning. As without in-depth knowledge of the inner workings no one would consider this possible and even in an "Expert" rank it would be highly unfair (+ extremely precise), at least in in my opinion! :)

Navigation

[0] Message Index

[#] Next page