Outdoor Buildings - Optimising, Visportals, LOD, SEED

[Dragofer]

There's plenty of info on the forums and the wiki about making outdoor environments game-ready, such as:

 

- Wiki, "Performance: Essential Must-Knows" Wiki

- Wiki, "Creating Large Complex Areas" Wiki

- Wiki, "Seed" Wiki

- Wiki, "City Street Visportal Tutorial" Wiki

- Wiki, "LOD Bias" Wiki

- Wiki, "Systematic Method for Adding Pathfinding to Uneven Terrain" Wiki

- Forums: "Using LOD" Thread

- Forums: "Easy Outdoors Recipe" Thread

 

These articles look like they're written for forests and city streets, but not so much for buildings out in the wilderness with climbable roofs and inner courtyards. There's extra challenge in this because the whole thing could go downhill from some views like the rooftops without careful planning, so I'd like to collect what can be done for this kind of map in this thread. It would be great if you can think of extra techniques.

 

Visportals

 

 

Here are front and top views of an example layout of a building with a courtyard.

In this view the visportals divide the outdoors into what's below and above the roof-line. This relies on it that joined visportals can open and close independently of each other. (Thread)

 

In this view the visportals divide the outdoors into smaller compartments along the walls of the building

 

 

 

Map design

 

 

With this visportal setup it could be a good idea to make the map long and narrow using cliffs, fences or a river. There are fewer positions from where one sees multiple visleafs along the sides, and the visleafs one sees have less inside them.

 

Kissing cylinders (Post) - to build a forest within brush cylinders for better visportalling. The cylinders can go all the way to the buildings.

 

 

 

Location system

 

 

In situations like these:

- you're standing on the roof and can't see objects along the walls below, but they still get rendered because they're in active visleafs.

- you're standing along the south wall but the visleafs around the corners are open so invisible objects along the west and east walls are rendered.

 

The location system can hide what you couldn't see from where you are. At the south wall almost everything along the west and east walls could be hidden. Every time you enter or leave a location, the location system can trigger entities that hide and unhide objects as needed.

 

 

 

LOD (Level-of-Detail)

 

 

LOD can be used to change to less-detailed versions of objects when they are far away. How soon this happens depends on the "Object Detail" video settings slider. LOD bias (Post) is a different mode that spawns different geometry depending on "Object Detail".

 

 

 

Fog

 

 

There are foglights and fog particle emitters:

- Foglights can be used to hide distant objects, in fact like a visportal, but they need attention if there should be no fog or weaker fog inside. Obsttorte made a scriptobject that uses the location system to change the density of fog when indoors (Thread). A problem with this is that when you cross the doorstep the fog will become clearer and let you see more into the distance, but you can have small L-shaped entrance corridors where the change can take place. This might not be practical if you have a lot of openable windows.

 

- Fog particle emitters or patches (Thread) can create a layer of mist along the ground. It can be used to shorten the distance from which ground objects become visible. A rule of thumb for performance is to use fewer more powerful emitters or larger patches.

 

 

 

.ase models

 

 

Repeating architecture can be converted into .ase models to save memory/polys and to make them into LOD entities.

 

Foliage decal patches can be cloned and rotated to make thick bushes that can border off the map edges. Convert to .ase for efficiency. (Thread)

 

 

 

SEED

 

 

Used to efficiently and randomly create vegetation, and to merge other entities to be more efficient with things like checking against the LOD system.

 

 

 

Misc

 

 

Some lights could be set to become noshadows at a distance.

 

 

Edited February 27, 2019 by Dragofer

[VanishedOne]

I have a manor not unlike the one in the diagram (though the path to the courtyard is a tunnel, which makes it more easily portalled off); the original plan didn't include an accessible roof, but I found the rooftops were quite enjoyable to romp over, so now the player can go up there. The actual portalling was largely dictated by the location system, though: I wanted a wind ambient around the rooftops but not below, so now there's a portal ring around the outer base of the roof.

[ShadeDrifter]

Theres one trick from hammer I remember. Essentially you have a brush that is transparent, but after a certain point it becomes less and less transparent until it's filled in and stops rendering what's behind it. Good for windows, not sure if you could do that here.

[SteveL]

Couple of random points:

 

There's another good tutorial you can add to your list. City street visportal tutorial, I think it's called.

 

Fog can do what visportals do and hide stuff in the distance just like a closed visportal.

 

You can turn fog off using location scripts to turn the fog light out. There might be non-scripting methods to do the same thing.

[ShadeDrifter]

This thread is coming at a convinient time, because I was thinking of making a map based off a doom fortress of solitude I made in minecraft, although I'll probably replace the instant death traps with enemies.

[Dragofer]

You can turn fog off using location scripts to turn the fog light out. There might be non-scripting methods to do the same thing.

 

Thanks, looking through the forums Obsttorte has made a scriptobject that changes fog density depending on location. It's quite good already especially when you can build your map so that the transitions are subtle, and it can be used in other situations too. But is there a way to have the fog just not render in a location?

 

 

Fog can do what visportals do and hide stuff in the distance just like a closed visportal.

 

Does this need to be set up? I'd check if this happens automatically later on.

 

 

Theres one trick from hammer I remember. Essentially you have a brush that is transparent, but after a certain point it becomes less and less transparent until it's filled in and stops rendering what's behind it. Good for windows, not sure if you could do that here.

 

That could be done using the LOD system to swap the skin of the window to less and less transparent glass as you get further away. It's a good idea, I don't remember seeing this being done in a DarkMod mission.

[demagogue]

The old tehchnique for making dense forests in T2 may still apply. I'd call it the kissing-cylinder technique. Make very large 'rooms' with really high walls arranged roughly circularly, then connect them at visportalled 'kiss' points, at angles where other VPs close when you pass through one. Then hide as much of the walls and esprecially edges of the kiss points behind big tree trunks and little trees and foilage, so it feels like you're just passing through trees. And add a lot of trees and foilage in the interior too of course. Then the area feels massively more open than it is. Baddcog's Relic: Left for Dead is a great example of this technique.

 

Edit. Sorry should have noticed the topic better. Baddcog's FM also shows you how to integrate big buildings into this set up. First, it allows you to isolate buildings into cylinders without it looking like you are. Second, you can let architecture go behind the 'walls' so it looks like they're just disappearing behind trees, but you can seal it so it's out of the leaf. Then the facade pops out in the playable area. And if you use multiple kissing cylinders around the structure you can follow the walls, or have the walls appear at various points, so it feels like a massive fortress.

[Bikerdude]

A good example of this to a certain degree is the forest in Alberics curse, and what i may do in-time for 2.04 is make a bunch of the trees LOD so that player on lower end machines can turn the detail slider down to gain some extra fps.

[demagogue]

Another thing to make that T2 uses are big tree branches. Then what you do is make your own trunk out of a patch cylinder and attach the branches to make custom trees. Maybe model big trunks too. But the point us model the trunk and branches separately.

[SteveL]

Separately modeled branches: that extra variety would probably have a performance cost, because the branches would need their own draw calls. Must stock model trees need just two draws, one for the woody bits and one for the foliage.

 

@Dragofer: Fog: I think it should just work. I've read the code but not tested it. You could test it using r_showtris to confirm whether a model stops being drawn beyond your opaque difference.

[demagogue]

For really big trees they're separated quite a bit, so you don't even have too many per area, like 3 or so trees fills the whole space. But it's important to arrange branches as you need for your space. Also, you're only talking about 3 or 5 or so branches for the whole tree to give the impression of foilage cover. I'm talking about huge, canopy type of branch structures, not like a single branch. It'd be worth it IMO, and not that much of a hit at all.

 

It wouldn't make sense for small trees, where you'd want the whole thing modeled as a single set-piece. You should think about big trees architecturally serving as walls and roof which you need to arrange for your space.

[SteveL]

That's right, I was thinking about small trees. I agree if you're using big chunks of foliage to fill the role of opaque walls, you can be as individual with them as you like.

[Dragofer]

The old tehchnique for making dense forests in T2

Great, that would work really well together with Sotha's Easy Outdoors Recipe for efficient .ase foliage bushes/boundaries. (http://forums.thedarkmod.com/topic/16159-easy-outdoors-recipe/).

 

SteveL: fog

 

I've fired up a foggy map I had lying around, unfortunately r_showtris isnt't affected by the fog. But it's definitely a great feature.

[nbohr1more]

One overlooked option is to use the lod_bias spawnargs.

The name is a bit of a misnomer as it doesn't really bias LOD transitions.

Instead it allows you to selectively spawn geometry depending on the Object Detail slider.

There is currently a bug where solid geometry leaves collision models when changing the detail level

but SteveL made a script that fixes it and it will be fully fixed in v2.04.

 

It was used for the exterior of Sir Talbots Collateral.

 

http://wiki.thedarkmod.com/index.php?title=LOD_Bias