3D Vanilla Bridge for Dummies?

I've picked apart the bridge in MAP01 of Scythe 2 and looked at several tutorials, but I don't think I know what I'm doing. Is there a way someone can dumb it down enough so I can understand how to make a bridge? I'm not interested (at this point) in Zdoom or Gzdoom mapping. I want to make a simple bridge for Vanilla, but none of my research has yielded anything other than confusion. Seeing as I've been mapping for over a year, I feel I should be able to grasp this.

Heh, you and me both sunshine. It relies on the control sector (which you build outside the map and join to another sector). My map has it implemented so feel free too look at that and note how the control sector is combined with other parts of the bridge (the two squares you see just outside the map note that I put it that far away in order to prevent the lift noise) bridges are basically like a lift is my understanding but has a bit more too it. I should be able to do this as well seeing as I have been mapping for a fair bit (more off than on however).

I also found all tutorials VERY confusing when I was learning this stuff. In the end I pretty much had to figure this out by myself.


Basically, 3D bridge consists of two parts: an invisible platform that instantly moves up or down when the player crosses corresponding linedefs and a bunch of middle textures that make it look like a bridge. Let's learn how to make an invisible moving platform first.

To make an invisible platform you first need to draw a new sector. Now look at its number, select its linedefs and make them both reference that sector (enter that number in the "sector" field for both front and back sides).

Now you want to make it move up and down depending on player's position to create an illusion that it's a thing you can walk over and under. To do that, first create a dummy sector somewhere outside the map. Select the invisible platform, then select that dummy sector and press "J" to merge them into one sector. Now draw another sector adjacent to it, let's call it a control sector. Give control sector's floor a height at which the player should appear when he is walking ON the bridge. Give control sector's ceiling a height at which the player should appear when he is walking UNDER the bridge. Yes, now control sector's floor is higher than its ceiling but you shouldn't worry about this, it won't cause any problems.

Now think about all the ways the player can approach the bridge. If he can get on the bridge from somewhere, make sure that before that he crosses a linedef that has an action 83 "WR Floor Lower To Highest Floor" and the same tag as the invisible platform sector. Same for getting under the bridge, except in this case use action 91 "WR Floor Raise To Lowest Ceiling". How do they work exactly? Action 83 will try to lower the platform's floor to the control sector's floor. However the control sector's floor is actually higher and because of that the height change will happen instantly (that's just the way Doom handles this). Same but in reverse happens for action 91.


Please do all this and tell me if everything works or if there is some problem. We'll deal with the visual part a bit later, for now you need to learn how to make an invisible moving platform.

I won't be able to implement this for a few days, because I can't run DoomBuilder on my Mac and my PC is at my parents' house. Next time I'm over there, I'll try it. Will it create any complications if there's a sector with a different height under the bridge?

Yes, then you'll have to use multiple sectors to make the bridge. I recommend to try making a simple bridge first to learn the basics. Start with easy stuff.

I tried to follow the instructions as exactly as I could, and it sorta works. I have a sector whose linedefs are the same number as the sector, joined to a dummy sector, which has an adjacent control sector containing the same number tag. I have the 83 and 91 tags for the over/under parts. What happens is, when I walk on the bridge, the floor suddenly raises. When I walk under, it suddenly lowers. So it seems to be working. But it doesn't really appear to be invisible.

You mean you see the floor texture and some HOMs when you walk on the bridge? Most likely this is caused by the nodebuilder that you're using. Try a different one. In Doom Builder 2 you can choose it in Tools->Game Configurations. I don't remember which is good for bridges but I think it's either zdbsp or zennode.

GoatLord said:

So it seems to be working. But it doesn't really appear to be invisible.

Just hazarding a guess, you probably have some sector joining to do. To help walk you through it, here's a pretty picture I've borrowed from one of Doomworld's tutorial pages.



The small squares are your control and dummy sectors in the void, you can ignore the blue sector 4 square if your bridge doesn't have impassible handrails. If the bridge appears to be working as expected, we can probably assume the dummy sectors at 5 & 6 have been set properly and ignore them as well. That leaves us with sectors 1 (the lower level), 2 (upper level), 3 (bridge/control sector) plus linedefs "a" and "b" to raise/lower the bridge.

The walkover section (red rectangle 3) should be OK if it's invisible when viewed from a lower level, but it won't hurt to check that the "d" linedefs have both sidedefs facing that sector.

The "c" and "e" linedefs, (with the mid-textures that form the visible part of your bridge) probably still have their front and back sidedefs facing different sectors, which is what causes the bridge to have a floor texture when raised and also contributes to the HOMs. Check that both sides of those linedefs and the backs of the "b" linedefs are facing sector 1. A quick way to do that in Doom Builder is to select sector 1 (outside the bridge) followed by every stray sector you find within the bridge spans that isn't sector 1 or 3 then hit J to join them.

Hope this helps. If not, I'll try my hand at doing a step-by-step tutorial map.

I find that any time I do stuff with sector trickery, BSP-W32 is the nodebuilder to use.

Also to add to what GreyGhost posted, you should make sure that DoomBuilder doesn't merge geometry between the linedefs of sectors 1 and 3.

Oh, for fuck's sake, now it's all gotten so confusing again. I can't be the only Doomer on here that just doesn't get this stuff. Ok, when I get some free time, I'm going to attempt this yet again. I appreciate all the advice, guys, but it so quickly becomes Greek that it's frustrating.

You could post the wad you made before that had a non-invisible floor and someone can tell you what's wrong. I bet you're not far off.

I think it's worth to say that the sector 4 is optional, just to make the things easier.

This may seem n00bish, but how do you find out what number a sector has?

I know the invisible bridge effect was used in some levels of Final Doom (both TNT and Plutonia) and in earth.wad in a different way to make a deep water illusion.

If you're using Doom Builder, the sector's number is present in the info bar that shows you what flat is used for the floor/ceiling (by default, I believe this info bar's on the bottom). Failing that, if you check a linedef that's feeding into that sector, you can get the numbers of the sectors on its front and back (assuming it's double-sided) in the window that lets you set the linedef's upper/middle/lower textures.

You can just mouse over a sector with the info window up and it will tell you. I'm lazy so here's a screenshot I found of DB in things mode; you can see where it says "Thing 79" in the bottom-left corner, in sector mode that will show you the sector number instead. Press ` to bring up that info panel if it's hidden.

Shadow Hog said:

If you're using Doom Builder, the sector's number is present in the info bar that shows you what flat is used for the floor/ceiling (by default, I believe this info bar's on the bottom). Failing that, if you check a linedef that's feeding into that sector, you can get the numbers of the sectors on its front and back (assuming it's double-sided) in the window that lets you set the linedef's upper/middle/lower textures.

OH! *Facepalm* Damn! I never paid attention to the top of the info bar!

Well, thanks anyway.

script 999 (void)
{
printbold (s:"JOE667 IS A NOOB AND HE KNOWS IT");
}

Basic bridge: 3dbridge.wad



in doombuilder 1.68:

- draw rectangle bridge sector
- lines mode, draw the lines inside the bridge to put mid textures on
- draw a sector around the bridge, or just add the two lines, to stop bridge sector from bleeding out
- sectors mode, click bridge sector, go up to "sectors" -> copy sector properties
- make dummy sector outside of map, go up to "sectors" -> paste sector properties
- highlight bridge and dummy sectors, press "j" to join them
- make control sectors on either side of dummy sector, use the floor of one control sector to control the bridge floor when it's raised, use the ceiling of the other control sector to control the bridge floor when it's lowered
- add lines 32 units away from bridge with action 91 to lower the bridge instantly so you can walk under it, use action 83 on lines before you walk over the bridge to raise it instantly
- sectors mode, highlight the bridge sector, lines mode, deselect the lines of the dummy sector, right click the bridge lines, set the front and back sector as the bridge sector, put STEPTOP as the front side and back side middle texture with a vertical offset of -128 (so that the mid textures are 128 units below the ceiling, at the bridge's raised height)

I'm resurrecting this thread because, after much trial and error, I finally understood what I was doing wrong. Basically, the floor/ceiling adjustment sectors that are adjacent to the dummy sector are NOT supposed to be tagged. I also figured out how to add a nice lattice without causing problems. So how would I add impassible handrails?

Create tiny self-referencing sectors on the sides of the bridge and give them such a ceiling height that would prevent the player from falling (remember that the player is 56 units tall). Scythe 2 MAP17 has an example.

I'm having trouble with that, but first I have a new question: What do I do when DB2 says it can't build the nodes for the map? I end up having to test/play it without nodes, making the bridge look glitchy. A floor texture appears and you can see the sides of the bridge when you jump off it. It works fine otherwise; you can go above and below it without problems.

I can't help you when the nodebuilder breaks, but it's happened to me before. :(

The problem is that it's a massive, really badass map that is totally worth finishing. It certainly can be played, but the lack of nodes makes middle textures look funny (they bleed through floors and ceilings) and of course the bridge looks wonky.

TimeOfDeath said:

- draw a sector around the bridge, or just add the two lines, to stop bridge sector from bleeding out

Eh? I never used this and I don't have any bleeding, perhaps your bridge is different.

I know how to do a vanilla fridge too.

GoatLord, sometimes in DB1 I get a similar error when trying to save/build nodes after I've joined some sectors. It saves the map but says it can't build the nodes, and the filesize is much smaller than it used to be. But closing the map, reopening, and resaving works fine for me and puts the map back to normal.

joe-ilya, maybe it's a nodebuilder thing, but bleeding always happens to me when making self-referencing sectors. You can see in DB1 in sectors mode, by moving the mouse over the self-referenced sector, then moving away from it and the sector is still highlighted (if there are no other lines close by that reference a different sector).

Saving and reloading the map doesn't work. Maybe I should try copying and pasting the entire map and all the things into a new file?

Remember when I suggested BSP-W32 above? Turns out it's usually the first to crap out when your level gets too big. Try a different nodebuilder if that's what you're using, if you can at least build the nodes, then sorting out 3D bridge stuff should be easier than coaxing BSP-W32 to work.

I'm still having an issue with the bridge bleeding the floor texture. Everything else is perfect. I took a good look at the 3D bridge example and noticed in the 3D preview in DB2, the bridge itself cannot be selected, although it can in the grid mode. What's that about and how does it relate to constructing a bridge that doesn't bleed?

The inability to select a self-referencing sector in 3D is pretty normal, AFAIK. Have you tried using different nodebuilders on the map yet? Another issue I have had before involving self-referencing sectors was the floor textures disappearing entirely or HOM'ing out entirely. I think having the sector touching more than one specific sector on all its sides might break the effect completely, but I don't know for sure.

SRS's are a hacky effect anyways, it's not surprising there's all kinds of issues with them.

EDIT: Updated file.

I haven't had luck with different nodebuilders. Here's the file, for MAP01 of Doom2:

http://www.mediafire.com/file/jd7xsvccdz9uchb/E1M4.wad

AS you can see, the bridge is rather long and complex. Maybe I got too ambitious and that's why it's crapping out...

I won't be able to take a look until at least 8 hours from now, once I get off work. But it seems very probably that a large SRS could have some problems like that. If no one picks it up before then, I'll definitely see what I can figure out.