BINedit is a 3D modelling program. It allows you to create and edit virtual 3D models. This is nothing new - all 3D modelling programs do this no matter what they were designed for, be it a professional program for most industrial forms of virtual modelling (like 3D Studio Max) or a user-created program specifically for editing one or more particular games (like BINedit).
The models these programs create are not truly three-dimensional. You cannot physically pick it up or touch its surface, or walk around it and look at it from the other side. They exist only within the cyberspace of your computer. The best you can do is look at a rendering of it on your computer's monitor, which is itself flat and only shows a two-dimensional picture. 3D models on a computer are in fact a complex set of numbers. When a command is sent to display the model, your computer does some mathematical trickery to display on your computer's 2D screen a rendering of the model. If you send a command to move or rotate the model, or to move your view around it, the computer redraws the display accordingly. So what you get on your computer screen is the illusion of virtual 3D space and virtual 3D models within it - rendered on the 2D surface of your computer screen.
This is where some people have a lot of trouble. It depends on how good you are at visualising 3D space - some people find it quite easy, but others have some problems. The complication is in the mathematical way in which it works - you don't need to know any fancy formulas or anything, but there are an awful lot of numbers involved.
BINedit (remember BINedit? This site is about BINedit) is designed for the viewing and editing of .BIN files, which describe 3D models using vertices (points in virtual 3D space) and faces (surfaces whose corners are joined to three or four vertices). Each vertex is defined using three numerical coordinate values: X, Y and Z.
Everyone should be familiar with using X and Y axes for 2D space. The X axis is the horizontal left-right axis, and the Y axis is the vertical up-down axis. Each axis has at its middle the value zero; X values are negative to the left of zero and positive to the right, and Y values are negative below zero and positive above. A point may be defined with (X, Y) coordinate values, so for example the point where the two axes cross at the middle of one another has the coordinates (0, 0), while a point at the upper left would have a negative X coordinate and a positive Y coordinate.
For the third dimension we add another axis, the Z axis, which runs forward (away from you) and backward (toward you). Z values are negative behind zero (on the side closer to you), and positive in front of zero (on the side away from you). Now we can define points with three coordinate values - X (left-right), Y (up-down) and Z (forward-backward). So the three axes will meet at (0, 0, 0). A vertex with the coordinates (653, -20, 7051) is to the right, a little way below and a fair distance forward of where the three axes meet.
Each vertex will have its own X, Y and Z coordinates which define just where in the virtual 3D space that vertex is positioned. BINedit numbers vertices starting at 0 through 1, 2, 3... and these numbers are used when defining faces - each face takes for each one of its three or four corners a vertex, so a face might be defined using vertices 3, 18, 109 and 852.
BINedit works with two different values of measurement - "feet" and "editor units". One foot equals 256 editor units (and for those of us who like the metric system, it follows that if 1 foot = 0.3048 metres then 1 metre = 840 editor units).
"Editor units" are the main unit used with .BIN models - these units are used for vertex coordinate values, so if a vertex has an X coordinate of 500, it's not a huge distance as the number might suggest, but really only about two feet off to the right of centre.
The imperial unit of measurement is thrown in to give the user a sense of real-world scale when working on their models. The Resize function of BINedit, for example, works in feet - it's much easier to estimate the overall dimensions of your subject in feet than it is with those editor units! This allows you to build a model using editor units, and then resize it to the correct size it would be in real life - or at least, relative to the other comparable models in MTM2.