Beyond flatland - 3D concepts

To represent things in 3D, we have to translate what we see into things that the computer can use to generate images. These methods will involve files with 3D geometry, pictures, and code. First, let's discuss how we position things in 3D.

To represent objects in 3D, we need their locations. A spreadsheet such as Excel uses A-Z (across) and 1-66 down (actually, A-XFD and 1-1048576). Computer graphics use numbers for all three axes. However, there are different ways to code these coordinates.

This applies to both the scale (what is one, an inch? One mile?) and what direction they go (is it Y or Z that is up?). To figure this out, we need to talk about coordinate systems.

Coordinates

We're all used to graph paper, grids, glowing spreadsheets with X and Y grids, or, numbers and letters like A1 and B1 in whatever spreadsheet program you use. Moving into the third dimension can be confusing, even though that's where we live. This is why I called this section Beyond flatland...