It's simply declaring where a surface is, based on points. If you're good at remembering stuff and at visualizing a 3d space, it cant be too hard.
Also, Outcast uses I-D for the rendering/modling of rounded surfaces.
And, theoretically, uses it for 'bugfixing'.
-Skunks
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Enginners can actually hear machines talk to them. The rattle in the car's engine teases soft, "I'll bet you can't find me." The computer hums an approving tune when the enginner writes an expecially briliant peice of computer code. The toaster says "Not yet, not yet, not yet." untill the toast pops out. An enginner who is surrounded by machines is never lonly and never judged by apperance. These are friends.