Ever wondered just how those models come into existence? This page was done especially to answer that very question!

First, the model's raw geometry is developed. For this, my favorite tool to use is Metasequoia, a 3D modeling application written by Osamu Mizuno. On the surface, Metasequoia seems very simple and cheerful, but under the hood, it's a very powerful tool.

I create the basic model, refine it until I'm happy with how it looks, and then I optimize the topology to make it suitable for unfolding into a paper model. For flat fold-over parts, I'll optimize the vertex connections so that the only connected vertices of a flat part are along the edge that the paper part is folded. Frequently, some geometry needs to be adjusted to take into account the thickness of, say, 110lb cardstock, and the adjustments make for a model that fits together better.

One other thing I check at this step is to make sure that there are no co-linear edges or erroneously unwelded vertices, because the program that I use to unfold the model later will create a glue tab along every edge, even edges along the same line, and unwelded faces will end up becoming disconnected parts during the unfolding process.

Next, the geometry is prepared for the texturing phase. I prefer to texture the models before unfolding, rather than painting over the unfolded development. This is because when you unwrap a model for texturing, you're able to optimize the layout and orientation of each model face to make texturing simpler. My favorite unwrapping tool is Ultimate Unwrap3D.

When a designer must paint over the unfolded development, they are stuck with this dilemma: parts that are unfolded to make assembly simple are often very difficult to paint over, and parts that are unfolded to make texturing simple often do not assemble as cleanly as they should.

Thus, it's much more desirable to separate texturing from unfolding as much as possible, and unwrapping the model first accomplishes that. The other nice bonus is that you don't have to worry about getting the unfolded development right at this point. If you had painted over the unfolded development and suddenly realized that you could have unfolded the part differently, you'd have to repaint the model in the new development, and that can be time-consuming.

When the model is unwrapped, what happens is that you're assigning new texture coordinates to each vertex in the geometry. Each set of texture coordinates is mapped to a rectangular 2D plane as a point, and when the dots are connected from point to point, the result is a wireframe description of the model's unwrapped geometry. This can be seen on the left hand side in the image for Step 2. That wireframe image is exported to use as a texturing template.

In this step, the unwrapped model's texturing template is opened in Adobe Photoshop, and I start painting the texture. I do this in layers, and I separate shading information from color and material information by organizing the layers into grouped layer sets. This way, I can tweak the colors, the shading, the surface detail, and the underlying material maps separately. As of late 2006, I started including layer sets for weathering, grunge, and other effects.

One of my favorite features of Photoshop is the ability to specify, save, and load layer styles. When I find a combination of layer effects that I like, I save them to a library for re-use in later textures.

While I'm painting the texture, I often keep Ultimate Unwrap3D open at the same time, and I toggle back and forth between Photoshop and Ultimate Unwrap3D to check the changes in realtime 3D as I go along. Ultimate Unwrap3D automatically reloads the textures every time I save them in Photoshop, which comes in very handy.

During this step, I like to play around with different color variations and see how they look on the model. This is made easy by the way I have my Photoshop layers set up, with separate layer sets for each of the different characteristics and properties that make up the surface material of the model.

This is the most time-consuming part of the process, because most of the surface relief and fine detail that normally would have been done in 3D needs to be done in the textures for models of this sort. Bolts, panels, vents, grills, rivets, servomotors, and things like that are done in 2D during this step, just like for a video game model done in the old days.

On to Page 2!