The Life of a Model

No, not that kind of model.

The image above shows Josh’s original 3D model of the cockpit versus the scaled-down version that will appear in the game.  And here it is actually running in the game.

Cockpit retopo in-game

The tiles around it are still just placeholders.  Updated and polished versions of those are on the way.

Taking a model from around 100,000 triangles down to around 1,000 is challenging.  All the little details of geometry are lost from the actual model, but you can “fake” them with an old graphics trick called normal mapping.  It can produce really excellent results if you are very careful.  Getting it right for the cockpit took the better part of two days.  I had to experiment with several different tools, and eventually found that the least painful method is doing it in Blender.  That was unexpected, because Blender isn’t really designed for this purpose, and it has a reputation for being… unreliable… to put it really gently.

It takes several iterations to really get all the detail correct, but it’s really worth it.  The gist of it is:

1) Build a low-poly model from the high-poly version
2) Use a tool (Blener, XNormal, etc) to “bake” a normal map
3) Test the normal map in a quick render
4) Say, “That looks horrible” and start over
5) Repeat steps 1-4 ten times
6) End up with a normal map that looks half decent
7) Go into Photoshop and manually fix problem areas in the normal map
8) Declare victory and move on to the next model

You end up with models that have orders of magnitude fewer triangles than the originals, but look 99% as good.  Depending on things like how close your camera will be to the object, they might even be indistinguishable.

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