[WIP]GTAModding Introduction: How GTA Works

[MenuET 205]

How GTA Works:

That article will give you everything you need to get started, not only on GTAModding, but also on any game you want and in Computer Graphics in general.

DISCLAIMER: This article is for people that never saw GTAModding before. For people that just want to make their own modifications in game. So its explained as simple as possible. It is actually for who never saw ANYTHING related to modding at all, and just want to get inside the modding world.

What this article IS NOT for: That article is not an step-to-step procedure telling you how to do everything you ever dreamt for your mod project.

Instead, WHAT THAT IS: That article serves new modders as an index to get started, to know the basic foundation of modding and know where to find content and material to start studying and practicing modding in general, whatever the mod project is.
It explains quickly all the steps of modding, explains which steps are, and what programs/software you do need to learn to master the techniques you need to do what you want. It gives the reader a shall explanation of EVERYTHING of how GTA and another games works since the core, the engine, the code, and the .exe itself. It explains even how the game is processed by your GPU and how it gets to your screen.

Okay lets get started shall we?


Engine:
Every videogame works on an engine. Even Grand Theft Auto.
Both of Grand Theft Auto engines, RAGE (IV/V) and RenderWare (III/VC/SA), has embedded:

1: A Rendering/Graphics engine
(that one is responsible for putting your 3d pretty on screen for you - you will work mostly with Graphics at Modding)
2: A Physics/Animation engine
(self-explainatory, unless you started gaming yesterday)
3: Scripted Building Blocks
(responsible for "blending" everything. The scripted mainframe. Makes the machine recognize game files and translate them to machine code. Youll probably work here, too)
4: An Sound Engine

Rendering Engine:

The process of rendering 3D, or the process that makes your 3d be pretty on screen, works as follows:

Primitives -> 3D Model/Mesh -> Lighting -> Shaders -> Rasterization -> 2D Materials -> Monitor

Primitives: Are the triangles. They are divided in 3: Points(vertex), Edges and Faces

3D Model/Mesh: You can mount any object with just triangles. And the 3d model/mesh is a set of these triangles (Primitives) all linked together.

Lighting/Shading: As the name says, the lights and the shadows of an object. Your model looks like this without them:

Lighting/shading makes it look like this:

A simple Lighting/Shading is common to see in many 3d editors like 3dsMAX, so you can see what you are actually editing/doing. However, that Lighting/Shading solution doesn't go with the model itself when you put it in game and in fact it looks more like the first image.
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2D Materials: A set 2d Images that gives the object its characteristics

Simple house facade. That images are put on the 3d model to give them color (1st image - Diffuse), tell the computer how the color (diffuse) will react with the game light (2nd image - Specular) being Black=Opaque and White=shiny, and many more. Usually (and mainly for Grand theft Auto) the regular 3d images are Diffuse/Specular and Normal (blue image that bends the light that hit the 3d model and gives the 2d material an illusion of being 3d.

All of that 2d images (also called "Maps") makes the 2d material itself. Here some more examples:



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Rasterization: The objects are 3d but your monitor screen are flat. Your Video Card has to convert your 3D in pixels so it can be read by your monitor.








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More:
Google: 3d Graphics Pipeline
For Further Reading:
https://www.ntu.edu.sg/home/ehchua/programming/opengl/CG_BasicsTheory.html#zz-1.

 

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If you wannna know more about that, i suggest you to go back to the high school and learn about vector aritmethic and Matrices. And of course, Calculus III (if you already know Calculus I and II.

The C++ libraries OpenGL and DirectX are responsible for adding to C++ the functions necessary for managing these primitives and thus making programs that make 3D reading, editing and rendering possible. See more by learning to program one of them libraries, if you want to get too technical. Both of them works pretty much the same.

But, if you just want to make 3D models right away, without learning about the "Coding" part, you can try and learn how to work with one of these 3d Editors:


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Working with 3d Editors


"Manual" Ones:
These ones are the most famous "manual" 3d Editing programs.

-3D Studio MAX (or 3dsMAX)

Payware, the most famous one. If you are active into modding you probably heard about that one


-Blender
https://www.blender.org/

Freeware. Not so famous on GTAModding and with almost no support for it, but the "Future", overpassing even 3dsMAX. (Actually on most of stuff it already did)


-SketchUp

Payware, Very easy to use. The favourite of novice modders by its ease of use, but without a lot of important features, it makes them move to 3d Studio MAX afterwards


-ZModeler

Payware, the most famous one for doing cars. If you are active into modding, you probably heard about that one. The most incomplete, however




-ZBrush and/or MudBox

Payware, Professional editor, different from all of the ones above. Most suitable "manual" editor for Characters, Clothing, difficult shapes and anything that is not "flat", but "organic")




-Sculptris

(Freeware, just like ZBrush, but with less features. Nice to get started)

"Automatic" 3d editors:
There are a lot of 3d Editors that lacks the low-level editing like 3dsMAX, but are more "automatic", which makes a lot easier the 3D work for some occasions. Many are very unknown on the GTAModding scenery but very popular outside.

-CityEngine
(link)

Specialized on mass making cities, buildings and roads.

Native functions are very poor, and relies on scripting to reaching its full extent.

But once you master the built-in scripting code, options are limitless, and you can make IV/V styled entire cities in a matter of minutes, even seconds.

For cities, roads, and buildings only

-PixelActive CityScape

Specialized on City modeling. Workflow similar to "City Mode" on SimCity and Cities:Skylines.
Very popular at early GTAIV modding days. Responsible for creating French Riviera.

Similar to CityEngine, but more "manual". You can make roads and in some cases, even terrain. Buildings need to be done separatedly

-L3DT

Specialized in Terrain Landscape and Nature.

Workflow similar to the "Terrain Mode" on SimCity4 or SC4 Terraformer

-WorldMachine
(link)

Specialized in Landscape and Nature. More complete than L3DT, but harder to use. You can achieve better results on it.

L3DT and WorldMachine are for terrains what CityScape and CityEngine are for towns, respectively.

-Revit

Made by the same creators of 3dsMAX

Specialized in buildings. Workflow similar to The Sims Build and Buy modes. Very few furnitures, doors and windows available. Needs 3dsMAX or other "manual" 3d editor to make furnitures and other objects.

Allows you to make custom doors and windows, and even less complex furnitures like tables and balconies. Very extense Objects libraries on the internet (200.000+), but all of them are too heavy for games, but can be easily edited on 3dsMAX or other "manual" editors to make them light enough to run on games.

-iClone

Specialized on characters. Workflow similar to character creators in various games, like the ones on The Sims and Fallout 4. Clothing and Hairs need to be done on "manual" editors like 3dsMAX and ZBrush, and then importing to the application

-Mixamo

Another Specialized on characters. Workflow similar to character creators in varios games, like the ones on The Sims and Fallout 4. Clothing and Hairs need to be done on "manual" editors like 3dsMAX and ZBrush, and then importing to the application

-MakeHuman
(link)

Another Specialized on characters. Freeware and Open-Source, letting you to modify its code and adjusting them to your needs.Workflow similar to character creators in varios games, like the ones on The Sims and Fallout 4. Clothing and Hairs need to be done on "manual" editors like 3dsMAX and ZBrush, and then importing to the application

-Marvelous Designer
(link)

Specialized in HD quality clothes. Became one of industry standard softwares for clothing.

Used in Assasins Creed, (insert a lot more of games here), and probably the very own GTAV.

 

Which one is better?
By convention you have learned here on GTAModding that "3dsMAX is better" because it has "gaming industry standard", "blah" and all sorts of stuff that i heard by the community out there. That could not be more false.


All of them tools are occasional (even 3dsMAX).
All of them are very good for an occasion, but terrible for another (even the praised 3dsmax). SketchUp lacks a lot of stuff that 3dsMAX has, but Sketchup can easily do some stuff 3x or even 4x faster. Some say that softwares like CityScape and MakeHuman (the automatic ones) are not professional. Lies. That softwares can carry work 10x more intensive than MAX (and are more comfortable to work with), with a lot of ease. Usually, that softwares can handle 90% or more of the work, letting you with only 10% or less to work on 3dsMAX or ZBrush. THAT 10% work, yes, you have to use 3dsMAX or other "manual" 3D editors. Yet, you have only 10% to do.
What one editor lacks other one brights.

French Riviera is an example of mod made with Automatic 3d Editors like CityScape.

Short answer: There is not a Software "One Size fits in all". You gonna need them all if you want to be optimal on your work.
Learn how to get the best and avoid the worst of them all.



Independently of the 3D editor you will use, you should watch the polygon (triangle) count. (explain about polycount here, relating it to primitives).

More triangles = More MB = More PC intensive = More Problems.


So, because of that, always control the complexity of your model. Always erase unneeded polygons. Use sufficient polygons only for the qualiy you need, nothing more.


Next up: 3D modeling process.

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Edited March 4 by MenuET

[MenuET 205]

Ill keep updating these posts as i go, and hopefully i can get it done.

 

Next Chapters:

 

-3D modeling process (including brief explanation of how 3d models are converted to GTA)

-2D Materials and UV Mapping (including softwares and procedures to learn to get started)

-Lighting/Shading (A more in-depth explanation what it is and how it works for GTA, with also links to get started, and also explanation on Prelighting/Shadow Baking and timecyc)

-Physics and Animation

[MenuET 205]

Reserved

Edited March 4 by MenuET

[deltaCJ 348]

Amazing introduction! I need to work on modeling my self, so these tutorials could help me out!

[Inan-Ahammad 318]

Really nice!Keep it up.

[Ndukong 35]

Cool tutorial intro. Looking forward to updates.

[skylumz 0]

Amazing explanation for beginners really cool you are doing this waiting for the next update!