What are areaportals & Hints?

dr.flexyjerkov · 04-19-2007, 10:38 AM

I been reading a few posts and i'm curious on what areaportals and hints are used for.
I've never really looked into the help for mapping and just gone with what ever i find works :P

GambiT · 04-19-2007, 12:08 PM

i dont know much about area portals but hints i am learning...

a Hint brush(one side hint all other sides of brush "skip") will tell Vvis(?) where to split the visleafs..proper use of this will drastically improve your compile time and even help with fps...*also use func_detail & func_wall(uses more memory than func_detail)*

ok its crappy i know...i dont have much time...i'm pretty busy at work...the first one at the top is a room with 2 windows...the bottom one is the same room with 2 windows BUT with a hint brush(with skip texture) in the windows..

the blue are the visleafs...see the difference?..

hope that helps...i can go further into it to help you but not right now....

own3r · 04-19-2007, 12:49 PM

Quote:

Originally Posted by dr.flexyjerkov

I been reading a few posts and i'm curious on what areaportals and hints are used for.
I've never really looked into the help for mapping and just gone with what ever i find works :P

http://www.student.ru.nl/rvanhoorn/o...794c04d3d71d61
This article talks about everything you will need to optimise in source, its really something which needs to be considered in the planning stage since certain shapes are required for things like hints.

Nezumi · 04-19-2007, 06:40 PM

When you compile your map, all the playable space is divided into visleafs*, which are concave 3 dimensional shapes. A hint brush will divide the leafs along the surface textured with hint. The engine tests visibility based on which leafs are visible to you from the leaf you're in. If you can draw a line from the leaf you're in to another leaf, everthing in that other leaf gets drawn. Collecting this data is largely what the vis stage of compiling does. There are usually a bunch of different ways the engine could potentially divide up your map into leafs, but there are are ways that tend to work better, which is why you want to use hints.

Suppose you're standing between two walls (the black rectangles) and there's some details on the opposite side of one wall (the red bits). If the leafs are divided up like in this picture, you can see from your leaf, C, into the leaf with the details, A. The detail bits will be drawn even though you can't see them.

But if you put a hint brush across the top of the walls like this, you can no longer draw a line from C to A without going through vis-blocking geometry. The game no longer tries to render anything in leaf A as long as you are in leaf C.

This is all in an ideal situation though. In reality, the engine is much more confused about what it should and shouldn't be drawing. 'Hint' is a very apropriate name.

Anyway, you can try to get it to do what you want.

Area portals are quite a bit different in many ways. For one, they are a volume, and not a surface like a hint. The space inside a hint brush is it's own special visleav (I assume. I mean, it kinda has to be, right?)
Area portals actively cull geometry, that is, if there's a doorway filled with a func_areaportal, then the game is actively checking to see what you can and can't see through that door. This means that area portals themselves actually reduce framerates (and you can somtimes notice a big spike of reduced framerate the first time you come into view of a particular areaportal), but the idea is that you can get the game to stop rendering enough other stuff to make it worthwhile. So use them sparingly. In a TF map, for example, it'd be a good idea to put one over all the front doors of a base, but not in doors between interior rooms.

*The proper plural for 'leaf' in the context of a data tree really is leafs, not leaves.

-=bingo-bango=- · 04-19-2007, 06:44 PM

Very nice explination on hint nezumi, ive always wonder what its for

Imbrifer · 04-20-2007, 03:26 AM

You can see it in action if you load up a map with hint brushes, then type "mat_wireframe 1" in console. You see everything as a wireframe, but only the portion of the map on your side of the hint is drawn(e.g. with Nezumi's example, you couldn't see things in areas A or D, but you could see things in areas B and C).

It's definitely useful, and its why TFC maps had so many cornery hallways and walls as soon as you entered the enemy base.

04-19-2007, 10:38 AM	#1
dr.flexyjerkov Join Date: Mar 2007 Posts Rated Helpful 0 Times	What are areaportals & Hints? I been reading a few posts and i'm curious on what areaportals and hints are used for. I've never really looked into the help for mapping and just gone with what ever i find works :P

04-19-2007, 12:08 PM	#2
GambiT Fortress Forever Staff Join Date: Mar 2007 Location: Baton Rouge Class/Position: Spy Affiliations: -=DoM=- Posts Rated Helpful 0 Times	i dont know much about area portals but hints i am learning... a Hint brush(one side hint all other sides of brush "skip") will tell Vvis(?) where to split the visleafs..proper use of this will drastically improve your compile time and even help with fps...also use func_detail & func_wall(uses more memory than func_detail) ok its crappy i know...i dont have much time...i'm pretty busy at work...the first one at the top is a room with 2 windows...the bottom one is the same room with 2 windows BUT with a hint brush(with skip texture) in the windows.. the blue are the visleafs...see the difference?.. hope that helps...i can go further into it to help you but not right now.... __________________ -------------------------------FF_Rock2(WIP)------------------------------ ---------------------------FF_RedGiant(Released)------------------------- --------------------------FF_Fragzone_G(Released)------------------------ --------------------------FF_Civibash_G(Released)------------------------ -------------------FF_Conc_G1(WIP)-------------------- -------------------FF_Hollow_G(WIP)---------------------

04-19-2007, 06:40 PM	#4
Nezumi Retired FF Staff Join Date: Mar 2007 Location: The Peoples Republic of Harmfull Free Radicals. Class/Position: Soldier, O Gametype: Doubble Mode Affiliations: Cassiotone Nation Posts Rated Helpful 1 Times	When you compile your map, all the playable space is divided into visleafs, which are concave 3 dimensional shapes. A hint brush will divide the leafs along the surface textured with hint. The engine tests visibility based on which leafs are visible to you from the leaf you're in. If you can draw a line from the leaf you're in to another leaf, everthing in that other leaf gets drawn. Collecting this data is largely what the vis stage of compiling does. There are usually a bunch of different ways the engine could potentially divide up your map into leafs, but there are are ways that tend to work better, which is why you want to use hints. Suppose you're standing between two walls (the black rectangles) and there's some details on the opposite side of one wall (the red bits). If the leafs are divided up like in this picture, you can see from your leaf, C, into the leaf with the details, A. The detail bits will be drawn even though you can't see them. But if you put a hint brush across the top of the walls like this, you can no longer draw a line from C to A without going through vis-blocking geometry. The game no longer tries to render anything in leaf A as long as you are in leaf C. This is all in an ideal situation though. In reality, the engine is much more confused about what it should and shouldn't be drawing. 'Hint' is a very apropriate name. Anyway, you can try* to get it to do what you want. Area portals are quite a bit different in many ways. For one, they are a volume, and not a surface like a hint. The space inside a hint brush is it's own special visleav (I assume. I mean, it kinda has to be, right?) Area portals actively cull geometry, that is, if there's a doorway filled with a func_areaportal, then the game is actively checking to see what you can and can't see through that door. This means that area portals themselves actually reduce framerates (and you can somtimes notice a big spike of reduced framerate the first time you come into view of a particular areaportal), but the idea is that you can get the game to stop rendering enough other stuff to make it worthwhile. So use them sparingly. In a TF map, for example, it'd be a good idea to put one over all the front doors of a base, but not in doors between interior rooms. *The proper plural for 'leaf' in the context of a data tree really is leafs, not leaves. __________________ TG: pretty much you have no idea how much i fuckin own at this game. TG: i bested no less than three flaming tornados and broke a huge wizard.

04-19-2007, 06:44 PM	#5
-=bingo-bango=- Spirit Studios Join Date: Mar 2007 Class/Position: Soldier Gametype: CTF Affiliations: Blue Team Posts Rated Helpful 0 Times	Very nice explination on hint nezumi, ive always wonder what its for __________________ Quote: Originally posted by Bridget [>] Who gives a shit? Tired of hearing about this...

04-20-2007, 03:26 AM	#6
Imbrifer Religious Stamp Machine Retired FF Staff Join Date: Mar 2007 Location: Mad City, WI Posts Rated Helpful 0 Times	You can see it in action if you load up a map with hint brushes, then type "mat_wireframe 1" in console. You see everything as a wireframe, but only the portion of the map on your side of the hint is drawn(e.g. with Nezumi's example, you couldn't see things in areas A or D, but you could see things in areas B and C). It's definitely useful, and its why TFC maps had so many cornery hallways and walls as soon as you entered the enemy base. __________________ Community Mapper 2morforever, 4play, attrition, gap, fragger and ff_training.

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