LOD system ?


May 16, 2003
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From a modeling perspective I think that right now it would be VERY VERY helpfull to know how valve is implementing the LOD(Level Of Detail) system.

Is this a fully automatic system with no user input, or will we need to make several detail level versions for each model?

If it is automatic, will we have any control over the situation?

Its kinda funny how whats old, becomes new again. I was building all My models for the old Domark Flight Sim Toolkit with 4-8 levels each back in the mid 90's. You would specify what the visible distance for each LOD version. It worked great, was easy to do, and required very little processor overhead to impliment. A real framerate saver! For example, in My Battlestar Galactica Flight sim the Viper model was about 1300 polys up close, it changed down to a 500-600 poly model a little farther away, then down to about 100 polys, and so on. The Final most distant version was a 4 sided wedge. I've been wondering why FPS games havent been doing this for a long time.

If the LOD system is automatic and scales models according to the current frame rate, then do we need to worry about having models that are too detailed? Some hints from valve would be cool right now.

The Punisher
I really think this is not included.
This is because HL² is an FPS.
This also means that everything is close to you.
And so it isn't needed to make different models for the LOD because there isn't a LOD.
This isn't hard to code a lover told me, not even for HL1
It does use LOD....

" was reading another HL site somewhere, and it pointed out that way back in 2000, talking about TF2, Valve discussed their LOD system. Gabe also mentioned the LOD system in the tech demo, and especially noted it when he was explaining how the game could work even on low end systems.

Here are the quotes from 2000:

"As announced earlier, TF2 will use a special licensed model Level of Detail system that lets the developers create and animate one extremely high-polygon model and the game will adjust the polygon count to keep a constant framerate. Up close, the models are incredibly detailed and lifelike. What's interesting about the LOD system used for TF2 is that it doesn't just reduce the polygon count based on distance, but based on the number of characters on-screen as well. Basically, you give the game a target framerate, and it will adjust the polygon level of all models at all times to try to meet it."

"They're doing a network LOD system where, say, the location of an opponent who is far away is always updated, but not necessarily his exact animation frame, since it would be hard to see his body position in the first place. Apparently, they're doing research into a whole new method of networking for Internet games and may give that a try as well."

Even though this info was for TF2, it was still the same engine and tech, and I'm betting this is how they can acheive a playable game even with a low-end computer: basically you tell the engine what framerate you want the game to run at, and it adjusts the LOD settings accordingly to any given situation.

If this is true, then it sounds like the game will tailor itself to look about as good as anything else could on the particular system you have and still be playable. So it's not like it will look like crap compared to the games you play on the system you have now. It will probably look pretty much as good (maybe a little better, maybe a little worse, given that it has more physics and stuff going on) as those you are used to."