Talk:3D model

Scope of Article

What is the intention of this article? To me it seems like an introduction to the use of models in Level Design with some scraps of vague or inaccurate technical facticles of dubious usefulness. Wouldn't Technical information about the structure of a model would be better placed in a dedicated article such as Anatomy of a Model or MDL? --Beeswax 10:56, 6 Apr 2008 (PDT)

This is a generic definition page, which ideally tells the reader what the subject is, gives a brief overview of its uses, and finally leads to other pages with more specific information.

Incidentally, it made no mention of Hammer until you added that stuff in the other day. Before then it was purely a definition. --TomEdwards 10:59, 6 Apr 2008 (PDT)

I disagree. It is currently too vague and disorganised to be useful as a definition. --Beeswax 11:12, 6 Apr 2008 (PDT)

Vague in what sense? Remember that this is aimed at people who have never even heard the term before. --TomEdwards 11:25, 6 Apr 2008 (PDT)

Technical information should indeed go in MDL, but that doesn't mean there isn't room for a high-level description of what separates a model from, say, a brush here. --TomEdwards 11:02, 6 Apr 2008 (PDT)

How about including some information on using models, or a link to a tutorial on inserting models into a map? Thanks.

Different types of models

• and then go on to explain (compare/contrast) the basic different types of model: eg worldmodels, viewmodels, 3D Skybox models, and then within worldmodels there are: gibs, Detail Props, (interactive) phys-prop models, (static) architectural-detail models, simple animated_models, character_models, etc --Beeswax 13:38, 6 Apr 2008 (PDT)

There has to be a cutoff point. World/View is the highest-level distinction to be made, which encompasses all of the other examples you just listed! --TomEdwards 07:10, 7 Apr 2008 (PDT)

I think there's a strong case for 3D skybox being a top level too - they're scaled differently, use scaled textures, are totally non-interactive, ... they are not interchangeable with worldmodels or viewmodels. Of course there's also the "fullscale" skybox props, which perform the same non-interactive role as mini-skybox, but live in the "world" physics-space :-( --Beeswax 10:41, 7 Apr 2008 (PDT)

The subcats of worldmodels I agree are not so easy to judge ... and I still haven't got my head round it yet;

• Gibs and Detail Props are odd because they can be models and/or sprites and are spawned rather than placed.
• Phys-models have many specialist features & requirements.
• Character (NPC) models are so intricate they definitely belong in a class of their own.
• And then there's the 'continuity props' like Items, Weapons, Wallchargers, etc.

These useful distinctions do need to be clarified somewhere... --Beeswax 10:41, 7 Apr 2008 (PDT)

Of course - but not here. That aside, skybox models are a good candidate - but are they common enough? --TomEdwards 12:50, 7 Apr 2008 (PDT)

Common Enough ? there's over 3100 worldmodels, about 24 viewmodels and 25 or so mini skybox models in the HL2 GCFs ... but that's irrelevant. The point is to distinguish between the different functions/use of the various types of model. A worldmodel will not function as a viewmodel, a skyboxmodel will not function as a worldmodel (not properly), etc, & vice versa. The design and purpose of each type is different from the others. The types are not interchangeable. --Beeswax 14:51, 7 Apr 2008 (PDT)

In it goes then! --TomEdwards 11:14, 9 Apr 2008 (PDT)

I'm glad we can agree on something :-) --Beeswax 15:08, 9 Apr 2008 (PDT)

Difference between Models and Brushes

• Models are used for almost everything in Source that isn't part of the underlying brush geometry. NPCs, physics objects, guns, and even some buildings, to name but a few examples, are all models.

Models are also not used for : the vast majority of game entities!. Does it not make more sense to mention the game entities that do use models?.

"Models are used for almost every 3D object in Source". Fixed! --TomEdwards 07:10, 7 Apr 2008 (PDT)

Except for Brushes, unless you're arguing that "models" (in a more general sense) can be made in hammer from brushes, eg a model house ? --Beeswax 10:41, 7 Apr 2008 (PDT)

Or perhaps you're suggesting that any geometry tied to an entity other than worldspawn is a model? --Beeswax 11:17, 7 Apr 2008 (PDT)

The full sentence reads "Models are used for almost every 3D object in Source that isn't a part of the underlying brush geometry". I think that covers everything. --TomEdwards 12:50, 7 Apr 2008 (PDT)

So without 'bloat': "Almost all 3D objects in Source are either Models or Brushes" ? Have you come across Plain English Campaign's Free Guides? I find them very helpful. --Beeswax 14:51, 7 Apr 2008 (PDT)

Right, only that implies that they are on equal footing to each other. "Underlying brush geometry" holds important meaning. --TomEdwards 11:14, 9 Apr 2008 (PDT)

I had ignored/overlooked that, yes. What meaning is that exactly? If it's important shouldn't it be more explicit ?--Beeswax 15:08, 9 Apr 2008 (PDT)

I think that would be better off as part of brush, which would cover it anyway. --TomEdwards 13:31, 11 Apr 2008 (PDT)

• Example Case: What is the main difference between a prop_physics and a func_physbox ? --Beeswax 15:18, 9 Apr 2008 (PDT)

Worldmodels

Why do you say that models are not part of the Worldspawn entity? What use is that statement? Models are not part of loads of entites, including Brushes. I believe you are misusing the term "world". Models are world objects - they are visible, collidable, interactable, etc they are not part of the HUD. I believe what you mean is that Worldmodels are distinct from Brushes because as far as Level Editing with Hammer is concerned, they are precompiled and uneditable. They can only appear in game by via an entity... but I'm just repeating my contribution that you deleted ... --Beeswax 11:12, 6 Apr 2008 (PDT)

Yeah, I can see that's a point of confusion now. I'm not happy with distinguishing between the two based on how they are created, though, since that isn't why they are different. Perhaps one day Valve will add model editing to Hammer - but they'd still be models and brushes, even if it was all compiled at the same time. :-p

Maybe the link should read "that isn't part of the underlying brush geometry". I'll make that change now as it's a definite improvement, but if you've got a better suggestion... --TomEdwards 11:25, 6 Apr 2008 (PDT)

How about " World objects can be either Models or Brushes. Models are ..." --Beeswax 12:32, 6 Apr 2008 (PDT)

I reckon I've worked that in to the current text now. --TomEdwards 07:10, 7 Apr 2008 (PDT)

Definition of "Model" in Source

• A model is a collection of points, or "vertexes", that form a 3D shape, or "mesh". The gaps between the points are usually filled with polygons, and these polygons are usually covered with a material.

This (nicely concise) technical definition applies equally to World brushes, which we agree are categorically not models. It could be a useful definition of a world object, or perhaps "BSP geometry", or even a "BSP file" ?!! --Beeswax 13:38, 6 Apr 2008 (PDT)

True enough, but would you - would anyone - ever describe a brush in that way? Either way, we need a description of what is being drawn on the screen when we see a model. --TomEdwards 07:10, 7 Apr 2008 (PDT)

I don't see what you can achieve by describing anything in that way. The point is that it does not define "model" as distinct from any other world geometry. (and BTW, what is being drawn on screen are called "pixels", what is being drawn in the mind of the player is a virtual "world" full of virtual "objects"... see Gestalt and of course ontology.) --Beeswax 10:41, 7 Apr 2008 (PDT)

There is a large difference to a newcomer between explaining what something is and merely explaining what something is not. --TomEdwards 12:50, 7 Apr 2008 (PDT)

I agree, but your statements do neither. --Beeswax 14:51, 7 Apr 2008 (PDT)

Really? They've fulfilled all of the criteria you asked for further down the page. --TomEdwards 11:14, 9 Apr 2008 (PDT)

And please, let's do without the philosophy. --TomEdwards 12:50, 7 Apr 2008 (PDT)

Please just skim over the first few paragraphs of the ontology article. Notice anything familiar about those keywords? "geometry", "entities", "properties", ... do you think that is coincidence? --Beeswax 14:51, 7 Apr 2008 (PDT)

The fact that Valve (well, iD) chose to name them "entities" rather than "purply squiggle thingies" doesn't have any impact on this discussion. So yes, as far as we are concerned it is coincidence. (Why am I even replying to this?) --TomEdwards 11:14, 9 Apr 2008 (PDT)

LOL! You don't think the Dev's choice of a standard terminology might be significant from the point of view of documentation then? --Beeswax 15:08, 9 Apr 2008 (PDT)

• A technical definition of a model (as opposed to an MDL, SMD, Brush,) etc should include:

((--- moved list to Anatomy of a Model page - no point cluttering up here. --Beeswax 10:41, 7 Apr 2008 (PDT)))

There's no point in having an incomplete list, a definition must be comprehensive. The more I think about this the more I think we need the Anatomy of a Model article urgently!... ;) --Beeswax 13:38, 6 Apr 2008 (PDT)

A definition must indeed be comprehensive, but it needn't and mustn't be comprehensive all in the same place at once. What's stopping that anatomy article being made and linked to? --TomEdwards 07:10, 7 Apr 2008 (PDT)

Erm, yes it must, and I already did . --Beeswax 10:41, 7 Apr 2008 (PDT)

Meh, whatever on the semantics. My point remains: we shouldn't bloat the article. Instead, we should link, as we're now doing. --TomEdwards 12:50, 7 Apr 2008 (PDT)

My point is that without more careful semantics this page will remain nothing but bloat. --Beeswax 14:51, 7 Apr 2008 (PDT)

Term "Model" used only in Hammer / Level Design context

In Hammer: In my ignorance of the really technical facts about different types of vertex geometry (which should probably go in MDL or an even more in depth 'technical' article), it seems to me that the most useful distinction between models and brushes is to help people deciding when and how to use them. AFAIK, models and brushes only 'behave' differently in Hammer? Note: I also changed this article category from "Modeling" (that misspelling bugs me every time I see it!) to "Level Design" to reflect that viewpoint. I honestly can't think of any other brush/model distinction that could be relevant in the context where the term "model" is used. --Beeswax 12:32, 6 Apr 2008 (PDT)

There's already a subheading on when you might want to use them. And you do realise that there is a whole section of the site dedicated to the making of models too, right? And also that they can be used by programmers? It's not just Hammer. --TomEdwards 07:10, 7 Apr 2008 (PDT)

Used by programmers ? No I didn't know that - please elaborate... --Beeswax 13:00, 7 Apr 2008 (PDT)

Choosing a model, parsing a model, controlling model animations, finding the location of a model, performing LOD on a model, lighting a model...anything dynamic happens in code. Hammer is just an interface to it. But we digress. --TomEdwards 11:14, 9 Apr 2008 (PDT)

Definitions: Essentialist definitions are of little practical (and debatable logical[1]) value. A useful definition is one that distinguishes this concept from similar concepts. ie:

• "a model is collection of vertex geometry, surface textures, predefined animated sequences, vphysics attributes, creativity, ingenuity, humour, fun, etc etc"

doesn't really answer any practical question such as

• "what do I need to know about models when I'm playing HL2?" (answer: nothing, it's not a significant concept in gameplay decisions.),
• "what do I need to know about models when I making a new Level for HL2?" (answer: diff between brush & model.)
• "what do I need to know about models when I'm making one for use in my mod/map?" (answer:lots - see Model Creation Overview, Anatomy of a Model, etc.).
• "what do I need to know about models when I'm designing an FPS Game Engine?" (answer: well, the boffins at Valve used a mixture of cartesian and spline geometry because ... etc).

Well, if we're going to do this point-by-point...

1. No text needed
2. Already covered
3. Added "See Model Creation Overview for more information" to the end of the para on model creation
4. That isn't the point of this website really, is it? :-p

--TomEdwards 07:10, 7 Apr 2008 (PDT)