vizportal

[nic485x]

what are visportals and what do they do?

[Springheel]

You need to visit the wiki: http://wiki.thedarkmod.com/index.php?title=Visportals

[Mortem Desino]

Visportals are invisible "windows" that seperate the level into chunks.

Depending on whether or not you can see through a visportal, the game will just discard parts of the level that don't have to be drawn on-screen (in order to save on fps and performance)

 

There's a good simple diagram and explanation here: http://www.modwiki.net/wiki/Visportal

 

A better in-game interpretation is here: http://www.iddevnet.com/doom3/visportals.php

[Bikerdude]

heh - the good old times - I remember what it was like when I first started with DR....

Edited April 21, 2010 by Bikerdude

[ungoliant]

yeah, i remember around the time when i had first downloaded DR, but had not started the A to Z yet, opened RttC with DR, and saw a huge "visportal" thing sticking in the middle of the street, and was like "wtf is that?" I think when I started mapping, I may even have had the audacity to start spamming new threads about content already posted in the wiki/forums too. Or did I. Ahh those were the days, eh

[stumpy]

although if you've worked with half life 2 then you know what a visportal is, but in hl2 they have a nasty habit of not working most of the time.

[Bikerdude]

but in hl2 they have a nasty habit of not working most of the time.

Hmm, well im finding that if they arent simple, they cause tdm problems also..

[stumpy]

well in hl2 if they dont work then the map refuses to compile, at least in doom3 they dont stop dmap from compiling the map.

 

in doom 3 some of the window textures count as being a hole, so if the windows arn't visportalled then the room isn't sealed.

[Fidcal]

Don't visportal windows unless they actually open or are transparent. Seal with caulk. Visportalling only seals when you aren't there.

[bambini]

Visportals are one of the things in DR that I just can't seem to get the hang of. The wiki entry was helpful, but I had a couple of questions:

- Does it matter which way round a visportal face is?

- Does it matter if a visportal is overlapping a worldspawn brush, or do the sides of the visportal face have to be touching and not overlapping the worldspawn brush to count as enclosed?

- If I have an irregular hole to plug, can I draw a large, square room in the void around the irregular hole and then place a visportal within that, cutting through the irregular hole?

- If I have a 2 floor building, will I need to make a series of visportals that completely separate out the two floors to prevent the engine from rendering both floors (including a big visportal outside the building)?

- if I have a visportal in a doorway, but above the doorway there is a small gap that goes into the other room, will I need to plug that small gap with a virsportal in order to make the doorway visportal work?

[Baal]

Visportals separate areas.

If you replace all visportal surfaces of a certain area with a stone texture, this area must be completely sealed off from the rest of the map. You can think of them as windows into adjacent areas.

Only the visportal surface of the brush counts and they should be as small as possible without leaking. If there's a gap, like in your door example, the portal will not be placed (you can check this with "r_showportals 1" in game).

[bambini]

Visportals separate areas.

If you replace all visportal surfaces of a certain area with a stone texture, this area must be completely sealed off from the rest of the map.

 

Gotcha. So if I have a room with two entrances, both entrances must be visportalled in order for it to work. If only one entrance is visportalled, then that visportal won't work at there isn't a seal. Much like ensuring that there aren't leaks into the void. Right?

[Fidcal]

bambini: In theory it does not matter which way round the visportal face is. It only matters where that face is. In practice occasionally I have had a problem and turned the visportal around and that fixed it - but that was more likely because turning the brush moves the visportal face to a slightly different position.

 

It doesn't matter if the visportal overlaps the surrounding worldspawn brushes. In fact I now deliberately overlap so I can see there is definitely no gap. Don't overdo it though and overlap beyond the surrounding brushes at some point!

 

Yes, as Baal says, you have to seal each area so if you seal a doorway but there is another gap then you must seal that too.

 

Whether 2 or 20 floors is irrelevant. Vertical or horizontal is irrelevant. 'rooms are an irrelevant concept. You need to seal non-simple volumes off from each other where there are bends. By non-simple I mean if one area is small and simple then you gain nothing by sealing it. You can also set visportals at an angle. Say you are looking towards an L shape then a visportal close the bend won't help much because you can see it. But push the visportal back into the recess and even angle it away from you helps much more. You need to either visualize in the editor or go in game and look what areas can't you see from a certain view? Say you are looking through a doorway into a large U shaped complex room then most likely it will help to visportal the far bend of the U.

 

Don't worry if it's confusing because it is a learning experience and while many postions are obvious, we all often scratch our heads and wonder where the best places to put visportals are. Keep checking which ones are working and which are open and which closed as you walk around your game. Bind a key to toggle them visible so you can check, eg, I use bind "KP_SLASH" "toggle r_showportals 1 0" in DoomConfig.cfg so I just hit keypad slash key. Use this on other people's FMs too to see how they are using visportals. Don't hesitate to open up their maps in Dark Radiant to examine where they are putting visportals so you can learn from them.

[Melan]

Lesson I learned the hard way: don't build too complex systems of several overlapping visportals.

[OrbWeaver]

Say you are looking towards an L shape then a visportal close the bend won't help much because you can see it. But push the visportal back into the recess and even angle it away from you helps much more.

 

It should be pointed out that in the example of an L-shaped corrido with only one visportal, merely moving the portal so you can't "see it" (i.e. because there are brushes in the way) won't be sufficient to cause it to close, because visportals are not occluded by brushwork (see second diagram at http://www.modwiki.net/wiki/Visportal for details).

 

Angling it away from you should work as you mention, as will adding a second visportal to the corner so that one cannot be seen through the other.

[Baal]

So if I have a room with two entrances, both entrances must be visportalled in order for it to work. If only one entrance is visportalled, then that visportal won't work at there isn't a seal. Much like ensuring that there aren't leaks into the void. Right?

 

Yes, both entrances must be visportalled or your room won't be a separate area. But the single portal may still work and you may end up with a bigger area containing the room and whatever the other entrance leads to. If there's a connection (a leak) from the room to the outside area, the portal will not work because it just leads from one area to the same area.

[bambini]

Gotcha. Thanks for all the help, visportals are really starting make sense now!

 

I think I need to practise a bit. Out of interest, when people are designing a room, do they make the room and then put in vosportals afterwards, or place the visportals as they go along?

[Mortem Desino]

Often (before I waste an entire day in DR ) I'll sketch out my idea on graph paper, breakign down the layout to only worldspawn and visportals. This helps me visualize where I should add an extra turn or tweak door placement for best performance.

 

But that can only be done once you're familiar with how visportals behave. For now, I would just experiment and use "r_showportals 1" in-game to figure out how these mysterious things work.