3D modelling has come a long way since its first use in “Futureworld” in 1976. While now 3D is used in almost every major film, even some TV shows and of course in video games. This article will explore modern 3D modelling and hopefully, by the end of the article, you should know more about; the applications of 3D, what is Geometric Theory, different 3D modelling techniques, commonly used 3D modelling software and technical constraints of 3D modelling.

A side on view of a Polygon Cylinder with “Smooth Shading” in Autodesk Maya 2011.

However, to understand any of that, you first need to know what 3D and 3D modelling is.

**What is 3D/3D Modelling?**

3D is something which has width, height and depth, the three dimension, or the X (Horizontal) Y (Vertical) Z (Depth) axis.

3D modelling, on the other hand, is the mathematical representation of the surface of any three-dimensional object using specialized software. 3D models are typically displayed on a 2D image (the vast majority of movies and videogames for example) but it is still being rendered in 3D.

**Coordinate Geometry**

As the 3 axis (X, Y and Z) go on forever in their respective directions, coordinate geometry is using two numbers to show the exact location of a point (for instance you could say 4, 8 to represent 4 across and 8 up).

This can be used to determine the distance between points, if the x and y axis have scale (so 1 = 5km for example on a geographical map).

In 3D Modelling it can also be used to rotate and transform and object based around a point.

**What is Geometric Theory?**

Geometric Theory is the mathematical study and definition of the measurements and properties in shapes.

**Dimensions**

A 2D object exists in 2D space consisting of the X and Y axis while a 3D object exists in a 3D space consisting of the X and Y axis with the addition of a Z axis (depth). 2D and 3D dimensions (and objects) are made up of vertex, faces and edges.

**Vertex**

A vertex (or vertices to use the plural) is the corner or intersection of a geometric shape and are thus the corner points for 2D and 3D objects. A vertex has no dimensions unless a second vertex is added to create a line known as an edge.

**Edge**

An edge is a one-dimensional line consisting of two vertices and adding another vertex would from a triangle (also called a face).

**Face**

A face is an object with at least 3 vertices and edges which mean the “minimum” would be a triangle. While they are 2D objects then can exist in a 3D space.

**Polygons**

Polygons consist of faces so they must at least be a triangle (or an object with 3 vertices and edges). An object with 4 or more vetices and edges is called an n-gon.

**Primitives**

Primitives are polygonal shapes that are used in conjunction to make a 3D object. These are include in most if not all 3D software packages (such as Autodesk Maya) and are thus the beginning of mesh construction.

**Mesh**

A mesh is a 3D model consisting of polygons and often includes the primitives discussed above.

**Wireframe**

A wireframe is a 3D model without visible faces, thus showing the outline of a 3D model which makes it easier to model as graphical details can get in the way while modelling.

**Applications of 3D Modelling**

3D Modelling is an incredibly useful tool for a variety of industries. This can include; Product Design and Marketing, Television and Film, science, Video Games and Architecture.

**Applications of 3D Modelling – Product Design**

3D Modelling is using in Product Design in a similar way to Architecture. It is used for the initial prototypes of a product. For example, if a company such as LG were designing a washing machine then they would use 3D Modelling software to initially get an idea of the design and look of the machine. This ensures they can be happy with the look of it before it would go into production. This can be useful to show off all the design features of a machine that may not be readily apparent on the finished, physical product.

As the design process continues for the washing machine the initial 3D Model could be iterated upon and improved at minimal cost compared to physically having to produce different prototypes of the product. Finally, you could having a working prototype of the washing machine exist in the 3D software in as much as you could have all the parts programmed to behave as they would in the real world thus ensuring that the product works and is safe before sending it to production.

This helps saving time and money on designs and products that would never see it on the commercial market.

**Applications of 3D Modelling – Film and Television**

In Film and Television, 3D Modelling can be used to have prototypes or “blueprints” for sets before they are built, which is akin to its use in Architecture. However it tends to be used more in CGI to create spectacular special effects that typically couldn’t be safely done in real life (although the lack of “reality” in CGI heavy films leads to criticisms that the film is soulless because it lacks the “real” element). It can also be used to create environments that are otherworldly or simply too costly or dangerous to film in (a film such as Avatar used a colossal amount of CGI imagery to portray Pandora, an alien moon that simply had no relative location on Earth to film in. Game of Thrones could be a TV show that mixes occasional CGI well with live-action shots, as the Great Wall in the North is a CGI model in some shots).

**Applications of 3D Modelling – Science**

3D Modelling has applications in science that draw parallels with its use in Product Design (in as much as it’s a valuable tool for concepts). While 3D Models can be used to simulate the human body to carry out virtual tests for medicines and to see what it would be like if a foreign body was introduced to a host (and a variety of other experiments) it can be used by people like Geologists to simulate Earthquakes and a variety of other natural catastrophes so that they can see the effects on cities and can in general be better prepared.

**Applications of 3D Modelling – Video Games**

3D Modelling is now one of the most vital parts of most modern day video games. While 3D graphics in games started out as lacking in detail and quite polygonal, the quality of the graphics steadily improved and combined with the use of CGI in films is one of the main driving forces behind how advanced 3D Modelling and graphics have become. While in the 90s the 3D Models were crude and it was only in the mid/late 90s they were used to created fully 3D worlds, it was arguably not until the HD era (2005/6 onwards) that 3D graphics in video games started to approach something akin to photorealism, although the debate about the uncanny valley (something with human features that behaves in a not quite human way).

Cloud from Final Fantasy 7. Note the crude character model as you can divide every part that makes up his body into polygons or n-gons.

**Applications of 3D Modelling – Architecture**

While in the past architects have had to draw blueprints for projects that were fairly realistic nowadays they make heavy use of 3D modelling software. This has huge advantages. It can be made as realistic as the person wants, it allows views from all heights and angles and you can actually go “inside” the structure which means that the architect knows exactly what the project will look like from every angle and precisely how it will be built, all without laying a brick.

**3D Modelling Techniques**

Through the use of 3D software there are multiple ways to create a 3D model, both simple and complex. This is known as polygonal modelling. While you have basic tools such as move and rotation there are multiple others to help make a 3D model. While the techniques are applicable across most 3D software packages, I will be using Autodesk Maya as a reference point.

**Extrude**

The Extrude tool allows you to select the face or edge of an object to create more divisions of the same size. Once “extruded” you are able to change the new face or edge with multiple other tools (such as rotate) to achieve your goal (for instance try making a pair of pillars with an arch connecting them only by using the extrude tool with one polygonal cube as a starting point).

A face has been selected on the polygonal cube.

With the face extruded, the new face can now be manipulated with the various other tools available in Maya. In Autodesk Maya you can use the extrusion tool by selecting the face or edge you wish to manipulate before clicking on the Extrude Tool in the Polygons Toolbar.

**Subdivisions**

A subdivision is when more vertices and edges are added to an existing face. Adding subdivisions will divide the face into equal sections with creates a smooth edge. In Autodesk Maya you can add subdivisions by selecting the vertices or edge you wish to manipulate and then going to Edit Mesh > Add Divisions.

**Bevel**

Bevel is the smoothing of an edge which is also called a bevel edge. In Autodesk Maya you can do this by selecting the edge or object you wish to bevel and going to Edit Mesh > Bevel. A shortcut is also available (although not permanent) by selecting the edge or object you wish to bevel and pressing “3” on most keyboards.

**Popular 3D Modelling Software**

**Autodesk 3DS Max**

Developer: Autodesk

3DS Max is a 3D graphics modelling software uses for animations and models. It is by some distance the most popular program of its type among games developers and all industries.

**Autodesk Maya **

Developer: Alias Systems Corporation then Autodesk

Autodesk Maya is 3D graphics animation software that is used to create videogames, animation and special effects (or SFX) for movies and television.

**Blender**

Developer: Blender Foundation

Blender is a free and open source (source code is made publically available) 3D graphics software uses for animation, SFX, 3D models and video games.

**Cinema 4D**

Developer: MAXON Computer GmbH

Cinema 4D is 3d modelling, animation and rendering software. It is typically used in films and notable movies to have used it for modelling and rendering include: Beowulf, Spider-Man 3, Inception, Iron Man 3 and Pacific Rim.

**ZBrush**

Developer: Pixologic

ZBrush is a digital sculpting program that uses 3D and 2.5D modelling, texturing and painting. What sets ZBrush apart from programs like Autodesk 3DS Max and Maya are that it’s modelling is more akin to sculpting.

**Limitations of 3D Modelling**

As we near the end of the article, I will briefly discuss the advantages and disadvantages of 3D Modelling.

The ease of use for 3D Modelling is a large factor as the software packages take care of a lot of the work for the user which means there is less cases of human error (say compared to 2D modelling). It is generally easier and thus quicker to use because the 3D Modelling software takes care of the lighting and other effects quicker and due to the Z Axis (or 3D) over only X and Y axis (2D) mistakes are far easier to spot and are almost pointed out by the software.

The example above shows that by not using the Extrude Tool on a subdivided face of the polygonal cube from earlier, the lighting and rendering of the object becomes, for lack of a better term, “confused” as the software package tries to approximate the lighting and rendering of it as if it were another object rather than simply an extension of the current object, despite the fact it is obviously connected to the current object. An error like this simply would not be visible easily in a 2D Software package.

However, there are disadvantages. These mainly include the learning curve with 3D software (as this writer can attest to!) and the difficulty in achieving certain effects which may simply be easier to do on a 2D software package because of the nature of it.

**Conclusion**

Now you should know about some of the applications of 3D, what exactly Geometric Theory is (and what makes up some of the various facets of Geometric Theory), 3D Modelling techniques, 3D Modelling software and some advantages and disadvantages of 3D Modelling.