Glide Question

I recently picked up doom speed running and have been able to do glides when positioned next to a wall (first picture), but can't seem to do glides where I need to go without the help of a wall. (like second one)

I have tried in Zdoom, GZDoom, and PrBoom+, but no matter how much I try I can't seem to get through these gaps. I don't know how to move precisely enough to line up correctly. Without a wall to line up against, I am completely lost xD. Does anyone have any tips whatsoever in lining up glides with midway gaps? I'd appreciate it.

In PrBoom+:
Move up to the gap and try to get close to the center of the gap, though a little bit towards the right of the gap. Once you are at the right position, align your angle with the gap: that is, you have to face exactly forward (you can usually determine your angle based on the tip of your weapon). Then, you have to move forward at the glide, and you will slowly veer to the left. Once you are close to the right position, your leftward movement will slow down and stop (though that doesn't always happen with glides that aren't south->north and I think west->east, though someone may want to correct me on this point). Then, you have two options: one is two move back and forward many times and hope for luck; this is very unreliable and, furthermore, you may start veering off to the left again and you'll have to realign yourself again. The other option is to turn up vertical sensitivity of the mouse a bit and slowly edge the mouse forward. This way, you're more likely to go through the gap.

In order to do a glide fast (particularly a flatface glide as in your example) you basically need luck. Aligning yourself quickly (particularly with vertical mouse sensitivity) and getting a fast glide require numerous attempts to get a good demo. I've never tried glides in ZDoom or GZDoom, though I believe ZDoom glides are possible and I assume they're done the same way.

Here's a short Sunder demo of mine that features a flatface glide:
doomedsda.us/lmps/1193/7/su05p011.zip.

Tried that, but I just veered left and never got stuck or stopped or anything. I've tried this in several different glide spots and keep getting same result :/

Im not sure if there is a -shortics command available with zdoom but it would make your life a whole lot easier with guideless glides. In certain directions you can get to a point where you'll physically stop assuming the correct angle and position, but as shockblast mentions inother directions you'll constantly slide. These specific glide directions are ridiculously hard without -shortics.

Yes, if you look at the Sunder demo I linked, I make sure to do the glide from the other side of the bars because I'm facing in the correct direction, even though I have to run around the exit. This is because if I did the glide from my initial direction, I would just slide past the gap. Your glide may be from the wrong direction, so you need to get it right away (which requires a lot more luck).

Here's a loooong beta version of a glide tutorial I wrote in case someone new to the game wants to figure out how this stuff works without wading through billion doomworld posts in random threads. It's probably more confusing than helpful though so read at your own risk. Would probably be more helpful with video tutorials but oh well. Chances are there's also tons of errors and typos.



Normally in doom, you can not go through a 32 unit wide gap. However, as doomguy is exactly 32x32 map units in size, with perfect positioning, luck, tons of practice and some arcane voodoo magics it's possible to squeeze through a gap of that size. That is called a "glide". Often very useful in speedrunning because it lets you skip large parts of levels. Glides work very differently depending on what sourceport and compatibility level you use. I remember speding over an hour wondering why I couldn't do doom2 map16 glide on prboom-plus then realising I had it on some weird complevel. I'd imagine especially the sourceports with freelook and whatnot will be very different from vanilla compatible stuff. I, and I guess most people that have put work into glides, only really have experience with glides in vanilla compatible sourceports (doom.exe, doom2.exe, chocolate-doom, prboom-plus with complevel 2/3/4). Since glides are mostly a speedrunning thing, they are usually done while using the built in demo recording (-record demoname). Doing glides with -record makes a HUGE difference because it basically reduces the amount of directions you can face, making finding the correct direction easier (or even possible). http://doomwiki.org/wiki/Turning_resolution_is_lowered_when_recording_demos for a better explanation. While there are demo formats which remove this problem/feature, I don't think I've ever seen a vanilla demo without the reduced turning resolution. Demos recorded for .wads that can't even be played on the vanilla .exes usually use this reduced turning resolution! For some reason "longtic" demos never caught on. Some ports have command line options for using the lower turning resolution without having to record a demo, like prboom-plus with -shorttics.

What seems to makes glides happen is getting in the correct fraction of a map unit. Checking coordinates with idmypos it seems like whenever I get inside the gap either x or y coordinate is 0x****0000, depending on which direction the glide is in. Obviously you can't visually judge if you're in the correct position or not. Best you can do is figure out when you're fairly close (less than one whole map unit from the gap close). Then you need to find a way of very slowly inching yourself towards the gap, which is probably best done with mouse movement - either playing with vertical mouse movement on (better for glides, at least on vanilla/chocolate doom) or using strafing with the mouse (much less consistent on vanilla/chocolate).

Difference between mouse strafing and vertical movement is that vertical movement can give you the smallest movement tic there is (GF1 if you check on a replay editor) while smallest movement tic mouse strafing can give is SR2 / SL2 (if you don't know what these mean, bigger number kinda makes you go faster... but doom movement code is very weird and there's a lot more to it than that). The bigger movement tics can lead to getting stuck one fraction of a map unit from the glide spot which will require repositioning, but more about that later. Now, with prboom-plus it's possible to get SR1 and SL1 tics with mouse strafing which is a massive advantage for anyone playing without vertical mouse move. It is still "vanilla compatible" in the sense that it will play back on original .exe, but as far as I know getting SR1/SL1 input with original .exes or chocolate doom is impossible.

For doing any of this stuff you'll want to have autorun off. In some ports it's a toggle and that's probably nice and all, but vanilla doesn't have that luxury. There having autorun off means you'll have to almost constantly hold down run. With run on, mouse strafing will always give SR50/SL50 tics which makes these tricks impossible. Not running also seems to increase the probability of getting "stuck" when positioning for east-west glides. tl;dr walking is good running is bad

Easiest category of glides is the guided glides, where you can use a wall for positioning yourself in front of the gap. For practice I'd recommend using vertical movement, even if you're not going to use it in a real run it should make learning how this works much easier. Doom2 map16 has one of the better known ones. Loopers 30uv run has a good example of this that isn't terribly fast, he does it with strafing though. Looper and xepop actually used a weird way of strafing towards the wall with keyboard and away from the wall with mouse at the same time but that's just weird, I'll let them explain that crap themselves if they show up in this thread. Individual level compet-n records are usually crazy flukes where the glides are done almost instantly and it's hard to even tell what happened in them. Just run against the "corner" of the black wall and the red skull pillar. Then facing directly east (this is where that reduced turning accuracy comes in handy) just move forward with mouse very slightly. For strafing you'll obviously want to face north or south, otherwise it's the same, just with the possible difficulty of not having as precise movement as with vertical movement. Note that you need to do this glide from east to west, gliding from the other side of the pillar from south to north is much more difficult. Why? Who knows. Doing glides, even guided ones, from south to north is obscenely difficult for some reason.

Sort of second easiest category is east to west guideless glide, as popularised by I guess cack_handed. In these positioning is slightly trickier as you can't use a wall to get close the gap, you need to use the gap itself. His pn08-019 demo ( doomedsda.us/lmps/946/3/pn08-019.zip ) has a text file explaining his method. Personally I do these by facing west, going to the right side of the gap, and then sloooowly moving left towards the gap by walking against the wall. Normal keyboard walk is fine, no need to mess with mouse movement yet. With luck, you'll end up stopping right at the gap (or with even more luck getting instantly through it, that's fairly rare though) - not running seems to increase chances of getting "stuck" like this. Then just push through with mouse movement. This is where novert makes a huge difference because it's possible to get stuck one fraction of a map unit from the glide spot (at 0x****0001 or something) when trying to get through with strafing, unless you're using prboom which changes the way mouse strafing works (even on complevel 2/3/4). If you get stuck like that reposition and try again. Vertical movement will never get you stuck like that which is why it makes learning this stuff easier, no need to worry about the completely random factor in strafe glides.

Last and maybe not least is the north to south guideless glide mostly done by yours truly I guess. The positioning for these is fairly similar to east-west ones, but you will almost never get stuck at the gap when running against the wall like in east-west situation. Visually the correct glide spot looks the "same" as east-west, there will be one column of pixels on the left side of the screen from the wall on the left side of the gap showing (assuming vanilla FOV, things will look weird if you play on some widescreen resolution with prboom). However you can't judge this only visually, there's a timing element in knowing when to stop after seeing that column of pixels show up. Then by walking back and forth using keyboard with a certain rhythm you can glide through the gap sooner or later... Note that this method is doable even with keyboard only play, mouse isn't used at all. I'm not 100% on how this even works but I believe there's timing in both knowing when to stop when positioning (so you're close to the glide spot) and to the rhythm in doing the back/forward movement. It's a very weird trick that took a lot of practise for me to figure out and I still can't pull it off that consistently.

Guideless glides in other directions just don't seem to happen manually. Same thing with guideless glides with normal turning. I've done at least east-west and west-east with longtics so it's possible, but it wasn't very fast. I haven't really put much thought into that though since demos are shorttics anyway. Some TASes also do west-east guideless glides, but I can't think of any TAS that did a south-north guideless glide. Aleksander Nikulin's Hell Revealed TAS had at least one guided south-north glide though. After you first figure out guided glides which, assuming they work at all non TAS, work the same for every direction, good place for getting used to how guideless glides in different directions work is plutonia map19 exit room as you can glide to the exit teleporter from every direction.

kunkun said:

Looper and xepop actually used a weird way of strafing towards the wall with keyboard and away from the wall with mouse at the same time but that's just weird, I'll let them explain that crap themselves if they show up in this thread.

This style comes from our coop-demo, if I'm not mistaken. You know, when all I got is an easy trick in map21 and I'm just waiting my partner stop sucking so much at this game (:D) to finally get there and then... my fingers stops cooperating failing me miserably at the fast glide, one may agree that something had to be done. The point being that this way of gliding is easy, reliable and because of the keyboard-mouse combo if I get through I already have a good amount of momentum and there seems to be less chance of accidentally "coming back" than in other slow styles. Also there's no need to disable autorunning since controlling speed is done with mouse and yet there's no need for vertical mouse. The awkward 90 degree turn is a small drawback and maybe it's a tad slow, I don't know.

kunkun said:

TAS

I'll just declare without proof that one can do instant glides (the guy slips through without slowdowns) in TAS (spoiler: map2 in 12s)
Edit: I heard it's common knowledge already D:
Edit2: I mean instant guideless glide ofc

Personally as a keyboarder, I find guided glides to be very easy if you don't face the gap at a 90 degree angle. Instead of that make the smallest possible turn Doomguy can make towards the wall and then just move forward. You will consistently bump into the wall really quickly several times and go through with a small chance of error. For glides such as map 16 you can even be more skewed and still make it through relatively easily.

Stuff I was very wrong about (so far):
It IS possible to get SR2/SL2 tics with autorun on. I don't know where I got the idea running+mouse strafe always gave strafe50 tics.
Aleksander Nikulins 30pl TAS has a south-north glide in map13. For some reason I thought that was west-east. After not very extensive research I have concluded west-east and south-north are equally BS. I managed to do that glide with mouse movement and lots of idmypos-ing but it took a while. Definitely not something that's viable in a run.
Map16 glide would be much easier from the other side of the pillar if the wall was on the left instead of right side. Manual glides as I know them seem to rely on approaching the gap from left as that's the direction you go to when running against a wall.

xepop: I had heard rumours about pressing three keys at the same time being really hard... and speaking of map02 in 12s is that movie ever getting finished :)

Cacatou, I tried that by going to the gap in map16 and facing east + turning one notch left, then running or walking forward. I couldn't really get either to work, usually I got stuck at whatever coordinates closeish to the gap. Same thing with different angles. Sometimes it did work but even then I didn't find it exactly fast or reliable. Not sure if I understood you correctly though. Is this method something you'd use in a 30uv run?

kunkun said:

is that movie ever getting finished :)

Probably not since he just keeps watching streams & Xena. Sanavapits!

Here's a demo with an almost instant glide demonstrating. The moment my angle is slightly towards the wall it works immediately. With enough practice you can get insta-glides quite easily.

d216.zip

Well, if someone is interested in these, here's an instant guided glide in doom2 map16 non-tas. I don't think it's rare when it's guided, but guideless would be really cool one to see non-tas.

no16yolo.zip

Sedlo's lv16-012 is instant, so was twister's cz-n entry lv16-011.94 adnd my sp16-010.94 (nomo). Basically they're not rare in map16, because you have a decent chance of getting them if you wallrun to exit. :P