Level Of Detail

[AgentXen]

I would realy like to know how the LOD "system" works.
Now does LOD Only Apply to Characters or does it apply to the map itself, or both?If it applys to the map how will it work?
Will it work like in gta Vc were from far away the buildings are just blocks? If so, Do you have to remake the map with lower LOD? And then just divide it and have it apear when you are at a certain distance.

 

[LoneDeranger]

Originally posted by AgentXen
I would realy like to know how the LOD "system" works.
Now does LOD Only Apply to Characters or does it apply to the map itself, or both?If it applys to the map how will it work?
Will it work like in gta Vc were from far away the buildings are just blocks? If so, Do you have to remake the map with lower LOD? And then just divide it and have it apear when you are at a certain distance.

It only applies to models (characters and props). Yeah VC is a very blunt and ugly example of how LOD works. Hopefully HL2 will be much more smooth.

 

[AgentXen]

If it dossent apply to the map what was all this talk about rocks shifting in the veachle scene? I am assumeing that the rocks are part of the map, not objects.

 

[Chris D]

Actually it applies to everything, but you normally only notice it with the draw distance and model details. But then there's the particle effects, map textures that will be toned down for lower end cards, lighting, shadows, water and reflection effects.

I believe maps themselves are unaffected. And dependant on how many versions of each model people want to make I guess they can create 5 as opposed to 3 to make the transitions smoother.

 

[LoneDeranger]

Rocks are objects. Unless they are part of the level geometry.

 

[$niper]

In the dune buggy video, the random boulders scattered along the path were models, not world geometry.

 

[AgentXen]

I hope You can Crash with them and Blow them up or Destroy them, since they are models.

 

[OCybrManO]

From what I can gather, in the Source engine there are at least two forms of LOD systems.
There is a model/prop LOD system and a terrain LOD system.
The model LODs are static and made beforehand.
The way Source generates terrain (takes a flat surface and tesselates it into smaller surfaces to allow curvature) from regular quake-engine-esque brushes lets it easily change the amount of detail you see from different distances or on different detail settings.

Here are some papers on terrain LOD systems (such as ROAM and Lindstrom-Koller algorithms) for anyone that is interested.
http://www.vterrain.org/LOD/Papers/

 

[nw909]

Originally posted by AgentXen
I hope You can Crash with them and Blow them up or Destroy them, since they are models.

The boulder would make the buggy explode, simple physics.

 

[Marauder]

Originally posted by nw909
The boulder would make the buggy explode, simple physics.

Not quite simple physics to program into a computer game. But yes, with all the work we have seen on Source, I am certain we will be seeing this. Hey, if BF1942 did it, I am sure HL2 has done it a hundred times better :cheese:

 

[Ahnteis]

There's a mod for HL that has LOD technology similar to what HL2 is doing. I don't remember the name, but it's "smear the queer" gameplay type. One player has a halo (angelic sort) and everyone else tries to kill him. You score points by staying alive with the halo.

 

[el Chi]

Originally posted by nw909
The boulder would make the buggy explode, simple physics.

A boulder making a buggy explode?
Explain...

Although manipulator rock-hurling fun. That's how you take out a flying manatee.

 

[ferd]

hmm, you could ask gabe...

 

[Nathaniel]

Originally posted by Ahnteis
There's a mod for HL that has LOD technology similar to what HL2 is doing. I don't remember the name, but it's "smear the queer" gameplay type. One player has a halo (angelic sort) and everyone else tries to kill him. You score points by staying alive with the halo.

I believe it was Holy Wars. A friend of mine did some of the playermodels.

A boulder making a buggy explode?
Explain...

Simple. Car crashes into Boulder. Car Explodes from impact.

AgentXen seemed to think we would be able to crash into a Boulder and make that explode from impact.

I hope You can Crash with them and Blow them up or Destroy them, since they are models.

 

[dawdler]

Simple. Car crashes into Boulder. Car Explodes from impact.

Assuming HL2 has Hollywood Cars (TM)

Not many cars that crash explode, they are designed not to blow up :dozey:

 

[OCybrManO]

Yes, Holy Wars pioneered the use of a model LOD system for HL and it was latered borrowed by The Specialists.
In this system it not only changes the level of detail of the model, but it totally gets rid of every weapon and player model that is out of your line of sight. This helps performance and to keep people from using thirdperson as some sort of wallhack (the character has to be able to see something, not just the camera).
I think more mods should have implemented this as it allows you to greatly improve the quality of the visuals with a very small performance hit.

 

[Chris D]

The only thing that really concerns me about the LOD system in the E3 video is that the draw distance in the buggy sequence was very very short. You could see the foliage appearing literally as you were two meters away from it and it looked really really bad. I hope they're planning on fixing it - and if possible, I hope we see evidence of it when the Buggy video comes out on Steam.

 

[jat]

boulder? doesnt it also depend how big it is?

the cart could send it flying or it could be pretty big stopping the buggy in its tracks.

 

[AgentXen]

Originally posted by Nathaniel

AgentXen seemed to think we would be able to crash into a Boulder and make that explode from impact.

What i ment was tha the rock would not explode, but get destroyed or deformed in someway or brake up into smaller parts, witch you can pick up with the "manipulator" gun.

Originally posted by Chris_D

The only thing that really concerns me about the LOD system in the E3 video is that the draw distance in the buggy sequence was very very short. You could see the foliage appearing literally as you were two meters away from it and it looked really really bad. I hope they're planning on fixing it - and if possible, I hope we see evidence of it when the Buggy video comes out on Steam.

I also noticed that the plants and othere small objects just apear exactly like the newspaper in the streets of vice city.

I really hope they will make the distance atleast 10 times longer. Enough to were we cant notice it. Or have the option of
"Draw Distance" in the menu or something.

 

[Phlek]

Chris_D, PlanetSide was like that too. You weren't able to see bushes and such until you were about 2 meters in front of them. But I thought PlanetSide did a good job of it, seeing the massive size of the maps.

 

[Ahnteis]

You also have to remember that a buggy travels considerably faster then a human.

 

[AgentXen]

Did anyone Noticed that close to the end of the buggy video clip, were Gordon gets out. There are Power Lines. And as the alien gunship blows Air at the lines, they start to wave. Bad Ass.


Edit:

Does anyone know or can tell if the lines are actualy modeled out? like not useing the picture of lines and the blue background.
Ex.

1.Modeled out
[]

[]

[]

[]

2. Useed one Brush with the texture of wires

_
| |
| |
| |
| |
| |
|_|

 

[Feath]

Originally posted by AgentXen
Did anyone Noticed that close to the end of the buggy video clip, were Gordon gets out. There are Power Lines. And as the alien gunship blows Air at the lines, they start to wave. Bad Ass.

That was the Barney video. It looked very amazing.

 

[LoneDeranger]

Originally posted by Feath
That was the Barney video. It looked very amazing.

It happens in the buggy vid also.

 

[Ahnteis]

They said the wires are modeled by taking several points and animating those points as if they were a wire and then filling in between the moving points.