Jump to content
Search In
  • More options...
Find results that contain...
Find results in...
Hock

Questions on Gliding

Recommended Posts

1. I've recently watched some TAS speedruns and I see that sometimes they can pull off a glide in the middle of two bars instead of off to the side. How do you do that?

2. Is there such a wad that focuses mainly on gliding?

Share this post


Link to post

Hi there. First off, I'm not a gliding expert but I've managed to do it a few times. The easiest glide I can think off is in Kama Sutra MAP05 (ksutra.wad). In the first room right after the start there is a glide which is really easy to do successfully.

All you gotta do is get a few speed and rush to the part between the wall and the pillar and force to go through it. All I do is forward (my key for that is W) and a bit of strafe left and strafe right (A and D) to get him "to the center". It's all about fullforcing him through the wall and the pillar with the forward key.

On the other hand, I've managed to glide Doom2's MAP22 by the Blue Key Door. Gliding is really hard to do there so there must be something out there that I don't know.

In time, gliding is not possible on Skulltag. It is, though, possible to do on PrBoom. That's where I try it :)

Share this post


Link to post

1. Read this thread to learn more about glides than you ever wanted to know. There's some discussion about "guideless" glides in particular on the third page.

2. Lots of wads nowadays are intentionally designed with time-saving glides, but I've never heard of a wad where gliding was required. That's probably a good thing; gliding is more interesting when it's a way to beat existing speedrun records on a map. If there was a map where you had no choice but to perform glides it would feel more like a chore. Then again, there's probably room in this world for a clever glide-based puzzle map, or some sort of gliding training ground.

Share this post


Link to post

The only wads I can think of where gliding is essential are test wads, made specifically to test gliding (I recall Kristian Ronge once threw one together, but I could be remembering it wrong). Maybe there are some buggy wads that are made possible by a glide, but I can't think of any offhand.

There are some wads with a lot of scope for gliding through 32-unit gaps, mostly because the author(s) didn't realize this was even possible. For instance, TVR! has a lot of such gaps.

Ksutra has a few (e.g. map32), but in that case, the authors had gliding at least partly in mind. The one in map05 isn't a 32-unit glide, but one of the "viable position to viable position through a gap that ought to be too small" type, like Doom2 map21's well-known one. As 1ntu says, ks05 is a particularly easy one - when I discovered it, I wasn't sure if it was even a glide at all. In the case of lv21, a precise position and angle of movement are needed.

1ntru said:

In time, gliding is not possible on Skulltag.

I haven't tried gliding in Skulltag, but unless it has changed the movement code from Zdoom (or made the player wider!), it should certainly be possible - just different. For instance, try STRAIN map07, and move directly backwards (walking or running) from the starting position. Do you get through the gap? In Doom2.exe, this glide fails in that case, as the high movement speed causes a drift to the side.

Share this post


Link to post

I use Skulltag as a main port because my Prboom for some unknown reason doesnt work on my computer. Anyways I am really good at doing glides, but when it comes to glides in between 2 bars aligned with each other i just cant do it. I have no idea how to perform that kind of glide. I've done it once by luck but other then that it just doesn't work.

Share this post


Link to post

As I understand it, the issue here is that in Doom2.exe (and ports that don't change the relevant code), you don't move in a perfectly north-south or east-west direction. As Creaphis pointed out, you move at a tiny angle to the axes. Thus if you move in a northerly direction against an object, you will also drift very slightly to the west. This means that at a certain point, you may be in perfect position to move through a gap, even if you started off not aligned with it.

In Zdoom (and presumably Skulltag), this doesn't happen. So unless you are already perfectly aligned with the gap, or have some way to make yourself aligned (e.g. a guide wall), you will never be perfectly aligned. If you push up against the wall, then you will stay pushed up against the wall at the same location. The reason the STRAIN map07 glide works in Zdoom is that you start off perfectly aligned for the glide - all you need to do is move directly backwards. Claustrophobia 1024 map01 is another example along very similar lines.

Hock said:

Prboom for some unknown reason doesnt work on my computer

Try Prboom-plus (try both software and OpenGL rendering) and report any specific problems to Andrey Budko. I'm sure the problem is readily solvable.

Share this post


Link to post

Well what i should have said was that neither Prboom plus or prboom work. Also open gl doesnt work on my computer either. :S

Share this post


Link to post
Grazza said:

I haven't tried gliding in Skulltag, but unless it has changed the movement code from Zdoom (or made the player wider!), it should certainly be possible - just different. For instance, try STRAIN map07, and move directly backwards (walking or running) from the starting position. Do you get through the gap? In Doom2.exe, this glide fails in that case, as the high movement speed causes a drift to the side.

Holy hell, you are right. I just went backwards in STRAIN Map07 and I did the glide like automatically. Well, the thing is that I've managed to do some glides on like 3 or 4 maps in PrBoom with a little ease but I managed to do none in Skulltag! Is it all about the angle and position? Because I got most of the glides I managed to do until now by fullforcing forward and "aligning" by going to the left left and right.

Share this post


Link to post

The thinking is that you just need to be perfectly aligned during the tic when you actually make the glide. Or rather, the engine only lets you into the gap if you are going to be perfectly aligned at that point (given your position in the previous tic and your momentum and acceleration). Creaphis's posts in the thread he linked to go into this in more detail, and explain that most "guideless" glides actually involve a tiny degree of "teleporting".

The problem with trying to align by moving left/right is that without a guiding wall to put you in perfect position, you are highly unlikely to end up in the perfect position to make the glide. The "drift to the left" from low-speed forward movement (with vanilla behaviour) gives a much better chance. Also full-speed forward movement may be useful in the east-to-west case, as I used here.

Share this post


Link to post

Does anyone have any suggestions for levels that have a lot or some glides in them? Also, levels like the bump obstacle course wad.

Share this post


Link to post

a glide is when you are like directly aligned with a 32 unit space and you go through it.

Share this post


Link to post

Didn't we have this same question, more or less, in another thread recently?

Anyway, TVR! is probably the megawad with the highest concentration of them. Of other well-known classic megawads, HR has a fair few, as does Plutonia. But they are pretty widespead in wads, especially in ones made before it became fairly widely known that a 32-unit gaps is begging or a glide.

Edit: yes, and it was you who asked! Merged.

Share this post


Link to post

Im trying to do some speedruns with some levels that include gliding but on prboom i cant seem to do it. It might be because I'm not using the correct compatibility options. Does anyone know what compatibility options you need on to perform a glide?

Share this post


Link to post

Glides are not complevel-dependent and there are no compat options that affect the player's ability to glide. All you need is precise controls and lots of practice.

Share this post


Link to post

Ahhh I just thoought maybe there was something with the compatibility options because I'm used to skulltag where i can do glides super fast and in this i cant even do them :P

Share this post


Link to post

Some people say that glides are much easier with vertical mouse sensitivity turned on. Maybe you're using it in Skulltag?

Share this post


Link to post

The reason you may have found some glides easier in Skulltag is that, presumably due to some changes in the way calculations are made in Zdoom (i.e. rounding errors and other such imprecisions removed), the player moves truly parallel to the axes, rather than drifting very slightly to the left (when moving forwards).

This means that if you start out perfectly aligned with a 32-unit gap in Zdoom (or Skulltag), and then move forwards, you will pass through the gap. In vanilla, the fact that you move very slightly to the left (when moving "purely forwards") means that you will not be aligned with the gap when you reach it.

Perhaps the simplest example of this is in STRAIN map07. Move backwards (walking or running) from the start position in Zdoom, and you get through the gap. In vanilla, you don't get through (except with extremely low movement speed - GB1 tics to be precise).

This is the reason why in vanilla, these glides can require a good deal of trickery (or luck). In Zdoom, though, they are only easy if you start off perfectly aligned. If you don't, then it may be hard to get aligned, especially as the drift to the left is actually a major method that speedrunners typically use to align themselves with a gap.

Going back to the STRAIN map07 example, try running around the map a bit (in Zdoom or Skulltag) and then return to the starting area. You'll probably find it rather harder to get through the gap.

Boom and MBF didn't change the game behaviour in this respect, and as far as I am aware, no version of Prboom has done so either. So, as people have said, the complevel doesn't affect this aspect of gameplay.

Share this post


Link to post

In vanilla, the fact that you move very slightly to the left (when moving "purely forwards") means that you will not be aligned with the gap when you reach it.

Heh, I sometimes try to align perfectly by using automap. Now I understand why it doesn't help immediately.

Share this post


Link to post

Reading the threads that have been linked to, and threads that are linked to by them, should provide a lot of insights. In particular, posts by cack_handed (he hasn't posted often, and many of his posts are about glides) and Creaphis should provide some useful ideas.

But no, there isn't a tutorial as such. Glides don't appear to be a simple skill to learn. People develop their own techniques (depending on their hardware and control set-up), and the understanding of the whole issue is incomplete. Each geometry seems to offer differences in the way the engine responds to user input. Presumably this is due to the details of the way the Doom engine makes its calculations. While people can certainly describe how they got a particular glide to work, this doesn't mean that the same method would work well with a similar-looking glide.

Note also that there are several different types of movement that are referred to as glides.

You'll need to get your hands a bit dirty if you want to become adept at glides. This isn't something where you can read a tutorial and they become easy. Note that some of the nicest-looking glide-based demos are the result of a long and frustrating recording session.

Share this post


Link to post

Earlier today i was practicing doing glides and i was getting them quite fast so i think i might be getting the hang of doing glides (:

Share this post


Link to post

Hi,

This is a huge necropost but since my question is related to the title of this thread and the answers found here, i decided to post my question here instead of creating another thread.
We recommended me to come here on Speedrun.com


So, cf. what Grazza said, especially this :

Grazza said:

The reason you may have found some glides easier in Skulltag is that, presumably due to some changes in the way calculations are made in Zdoom (i.e. rounding errors and other such imprecisions removed), the player moves truly parallel to the axes, rather than drifting very slightly to the left (when moving forwards).

This means that if you start out perfectly aligned with a 32-unit gap in Zdoom (or Skulltag), and then move forwards, you will pass through the gap. In vanilla, the fact that you move very slightly to the left (when moving "purely forwards") means that you will not be aligned with the gap when you reach it.

I'd like to know which are the differences about gliding in the various versions, and/or what should be the version(s) used to run the game properly.

For a little background about why i ask this question, it's because in a speedrun event lasting several months to learn 10 games to speedrun, Doom II is part of the second batch of 5 games (for now in category UV-Speed / Any% UV, it may change). And we choose Chocolate Doom at first to finally come with ZDoom. That's why i'm here.
For now i never played this game, only saw 2 guys participating in the event streaming it, and the WR in the category as well as the TAS.

Thanks in advance o/.

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×