Theory and Application of 3D By Natalie Coombs
Applications of 3D In the modern world, the media has continued to grow and develop into a multimillion pound industry, with video games, films and television beginning to dominate what people do with their spare time. 3D models are used very frequently within such media, as well as others. But how are they used exactly?
Animation One of the most obvious example of 3D models being used in the media are within animated movies, such as “Toy Story” or “The Incredibles.” Generally, the more realistic and complex the films look, the higher the polygon count and the longer the rendering times, meaning that they take longer to make. This is why Pixar films typically take a few years to create and release.
Film and Television 3D models are used many times in films and TV to create both large, seemingly living creatures, such as the dragons in “Game of Thrones” or the Ents in “The Lord of the Rings,” and to create environments for films like “The Jungle Book.” Many of today’s special effects are done with the use of 3D models. These effects are pre-rendered, meaning that they are not generated in real-time. This means that these models can have a high polygon count, and there aren’t very many limits to what you can do with the models.
Video Games Just like animated films, video games feature many 3D models, almost entirely consisting of them. The difference between the two, however, is that while playing a game, the 3D models are usually rendered in real-time, and so there are limits to what you can display on the screen at any one time, and there is a lot more processing required. This also means that the models can’t use as many polygons as the ones in a 3D movie.
Education 3D modelling can be used to teach people about things such as organs, atoms, engines and other complex matter which may be expensive to procure in real life, or which could only otherwise be shown in sketches or drawings. It allows for more in-depth analysis and examination. It also allows for learning online or on a computer rather than from books, which allows for a more interactive and interesting lesson.
Displaying 3D Polygon Animations
Displaying 3D polygon animations has become a lot easier in recent years, and as such, 3D models have become much more advanced and detailed than they were before. The best example of this would be to look at the evolution of video games. Character models from games released in the 90’s look a lot more primitive and “blocky” than today’s more realistic looking characters, and this is in part due to the evolution of software and game engines which display these models.
Geometric Theory
3D models are a conglomeration of smaller shapes, called polygons. These shapes usually consist of triangular surfaces, which can be edited and molded by manipulating the vertexes (corners) and/or the faces of the triangles. The more polygons within a 3D model, the more detailed the model looks, and the longer the model will take to render, as there can only be so many polygons rendered at any one time.
Mesh Construction
There are several ways to create a 3D model. These include: Box Modelling- This is when a 3D model is formed from a basic cube shape, which is then molded into the desired shape using subdivision, stretching and/or extruding. This is one of the more basic methods, but it is harder to add too much detail to the model with this method than with the others. Sculpting- Sculpting is similar to box modelling, only using a sphere shape rather than a cube. The name comes from the way the sphere is “sculpted” as though it’s from a lump of virtual clay. Extrusion Modelling- Extrusion modelling involves creating a model from nothing more than a line, which can be stretched and extruded into a face, and then further manipulated to create edges, vertices and other faces. Extrusion modelling can be relatively fast, however creating curves can be difficult due to the need for a large number of polygons.
Common Primitives
Primitives are shapes which are usually pre-made and can be used as a base to create a model. They usually have a fairly low polygon count, and are available as basic shapes in most 3D modelling software. Some examples of common primitives include: Cube Flat Plane Pyramid UV Sphere Isometric Sphere Cylinder
Textures
Textures are images which are wrapped around a 3D model to add colour and detail. They can be manipulated within the 3D modelling software, or even on a program such as Adobe Photoshop.
Raytracing Raytracing is a method of generating shadows using light beams to shine through pixels.
Bump Mapping
Bump mapping is a method of texture design wherein you use shading and highlighting to add detail to a model and add details to a flat surface. This means a model doesn’t require as many polygons to generate a desired effect.
3D Development Software
Modelling Software
There are a lot of different programs which can be used to create 3D models, many of which can be downloaded for free from the internet. Some of these include: Blender- A basic, open source editing software which can be used with relative ease, meaning it can be used by people who are new to modelling with various tutorials available online. Autodesk Maya- A more sophisticated and professional piece of software which is commonly used to create models for video games, including “Pokemon.” It also includes a feature which allows you to edit textures, as well as other tools to create more detailed models. Cinema 4D- Another piece of professional software which is commonly used for a variety of things such as designing architecture or designing parts for engineering.
API
Graphics API is a type of coding which interacts with the graphics card in order to achieve a desired effect. Two of these include OpenGL (used for mainly for PS3’s and PC’s, and can be written using Java and C++) and DirectX (a Microsoft API which is used for Microsoft products, such as the Xbox and Windows).
Constraints
File Size
File sizes are constraints which usually effect video games. Big games which require a lot of memory (due to factors such as the level of detail in the game or simply the game’s length) are sometimes released on multiple disks so that they can release as much content at as high a quality as they are able to. This happened with games such as “Final Fantasy VII,” “Resident Evil 2,” and, more recently, “LA Noire.” There are also some films which are released on multiple disks, such as “Dances with Wolves” and “The Lord of the Rings,” and TV shows are released with many different disks depending on how many episodes are in a season. Recent advancements, such as the BluRay disk, means that disks can be manufactured that can hold larger file sizes, and many games release parts online rather than including them on the main disk.
Polycount
Polycount simply refers to the number of polygons that a model consists of. The polycount of modern games are much higher than games that came out even 10 years ago, due to the more advanced software being able to process higher polycounts which can be rendered in real time. The lower the polycount, the smoother and more fluid the game runs.
Render Time
Render time refers to the amount of time it takes to render a model or models. The higher the polycount, the longer the render time, as the more processing power is needed.
Internet Speeds
As technology is frequently becoming more dependent on the internet, so too is gaming. This means that a lot of games rely on the internet in order to effectively render their models, which can mean that people with slower connections experience issues with framerate and lag. This mainly effects games which utilize the internet for things such as online multiplayer. Downloading content from online can also depend on internet speeds, as the slower the internet and the bigger the file sizes, the slower the download speed.