Creating 3d video games 3 - Crash course in 3d graphics

Before we begin using Blender to model our 3d world let's cover some basic 3d graphic terminology. Having an in depth knowledge of 3d graphics isn't always necessary for creating video games but some basic knowledge is required. Even if you don't plan on creating or editing 3d models for your game I would suggest learning some of the basics to help you better communicate with your modeling team.

3d coordinates

A 3d coordinate system shows a location in 3d space by using three axises represented by X,Y and Z(x,y,z). The above graph shows a common 3d coordinate system.Where X is width , Y is height and Z is depth. Each axis is represented by a line. Where the three lines intersect is known as the origin. The origin is the center of our 3d world. In order to find a location in 3d space we start by counting out how many units (inches,feet,world) the object is from the origin. Note each direction is represented by a positive or negative. An object at position (10,-15,5) Would be 10 units to the right , 15 units below and 5 units forward of the center of origin.

Polygon or Face

Polygons or faces are any shape with a flat surface. Above we have some examples of polygons. A polygon can have an unlimited number of sides but must have at least 3 sides. The most basic polygon shape being a triangle.

Edge or Line

An edge is represented by a line. These lines make up the border of our polygon. For example our triangle has 3 edges. These are the three lines that connect to make up our shape.

Vertex or Point

A vertex (plural vertices) is represent by a single point in 3d space (x,y,z). Look at the image above you will see white dots that mark where each edge connects. This white dot represents a vertex. Vertices represent where two or more edges connect.

Model

A model is a 3d object made up of polygons. Models can be something simple such as a cube or plain or complex such as a human or animal. Below is a wire frame 3d model of simple cube. The vertices have been marked. Notice it is possible for polygons to share edges and vertices with other polygons.

Now you have learned some basic 3d terminology we will move on to creating our first 3d stage. For those of you who would like to learn more about 3d graphics visit http://chortle.ccsu.edu/vectorlessons/vectorindex.html The people at Central Connecticut have provided a free course along with download in computer graphics.