Visportal arrangement library?

[nbohr1more]

I'm sure that the jury is out regarding a great deal of where one would say the "optimal" visportal arrangement would be for different scenarios but I thought it would be cool to have a thread that collects VP arrangements of either common or tricky areas so that mappers could compare and contrast.

 

I was thinking of the common scenario of an open door-like entrance between two large areas and thought that a "fan-like" pattern of VP's would close according to your view parallax:

 

 

\ \ |**| / /

*W**W

__ **___

**|**|

--- ** -----

1 2 3 4 5

 

(See attached JPG)

 

 

(Obviously the W would be where the VP's come very close to each other then fan out from there.)

 

My presumption is that as the player moves from position 1 to 5 different pairs of VP's will close?

 

Anyone wish to comment or share their tricks?

 

(Forum formatting is not consistent enough to preserve the intent of my ASCII art )

Edited April 7, 2011 by nbohr1more

[Baddcog]

I think that would be overkill.

 

Vis portalling isn't complicated so why make it so?

 

The best things to do with vis portals:

 

keep them as small as possible.

give them a nice square seal on all sides (can be masked with f_s's to hide the fact it's a square seal)

[Serpentine]

http://optimization.interlopers.net/index.php?chapter=hints

 

While its not the same terminology, its the same ideas for the most part - a good guide and good insight.

 

Pretty much everything can be done without portal spam, rather keep design constraints in mind while building, at worst learn some nifty ways to make area rooms less noticeable.

[Baddcog]

The problem with showing Hammer tuts on optimizing is while the engines use similar techniques they are completely different.

 

ie:

 

Doom3 use visportals and ONLY visportals to optimize. While walls give seperate areas to 'seal' visportals the walls themselves don't block players view. Thus the only optimizing is done by not being able to see through a portal, and portals can only close if they can't be seen through another portal (regardless of walls making it appear they can't be seen).

 

Hammer uses a vis leaf system. This breaks up terrain into smaller areas (actually work a lot like Dromed does in that respect).

Leafs (open areas) are rendered or not based on how the engine cuts them up, and whether or not they can be seen from ANY point within the leaf the player is in.

Walls DO help block vision.

Area_portals can be added by author to further optimize (close areas off and cull models). But they close depending on if player can see them from anywhere within the leaf they are in.

Hint brushes can be used to cut/change visleafs to further optimize.

 

----------in short

Doom3 can only cull terrain if visportals are added properly.

 

Hammer culls terrain/objects with a leaf system on the fly. No work needed from author. But added work will bring better results.

 

So Hammer tuts have very little bearing on optimizing for Doom3. They are completely different engines that just happen to have VERY similar editors.

[Serpentine]

Vis leaves are approx the same, except for Hammer generating some automatically(and doing that badly, meaning you want to hint them). The important stuff is about the use of hints (normal VP's) and area_portals (somewhat like distance closing VPs).

 

The ideas of placement and logic are important, names are not.

[Baddcog]

Yes but you can't add hints in DR can you? Because all they do if break up leafs.

 

And the entire leaf/hint thing is beyond what DR does.

 

So looking at how to optimize for an engine that 'pre-optimizes' and one that doesn't optimize at all, it's completely different. To a slight degree they are the same, but in Hammer terrain culls JUST based on how the visleafs work.

Doom3 doesn't have that system at all so how the portals close is completely different, and if you build according to Hammer the results you get are not what you'd expect/want in Doom3.

 

Hints are not at all like VP's, they only change the structure of the leafs. Making them worse or better.

 

Area Portals are almost exactly like vp's. In that they cut leafs and also cull objects/terrain behind them. However due to the leaf system in Hammer area portals aren't required, they just help you get better performance unlike Doom3 where they are absolutely required.

AP's also close differently than VP's, they can close by being blocked by worldspawn walls, and that's the confusion most people have about vp's is that if they go behind a wall it seems as though they should close, whereas they only close IF they can't be seen through the next vp.

 

I just think getting people to think about Hammer's optimizing process will just confuse people about why they can't get DR's to work, as they are different enough to matter.

If you optimize a hammer map like a doom 3 map it will be very optimized, if you do a doom3 map like a hammer map it might not be optimized at all.