3MOD

3mod Interface		Cartoon Outline Mode

3mod is a simple 3d modeling program which uses OpenGL to render. It supports triangles, quads, and bezier curves. The program supports basic texturing, lighting, and cartoon outlining. Cartoon outlining is not done by computing normals and finding edges shared between front facing and back facing polygons like in the popular algorithms. I use my own algorithm, which does not depend on surface normals, and instead uses depth buffer slope. My method is completely hardware accelerated by the fixed function OpenGL pipeline, unlike the most common methods, which either involve custom shaders or quite a bit of cpu processing eac frame.

Click to see a close-up view of the 3d cursor

This program is missing several features, but includes a unique feature that I have not seen in any 3d modeling program yet: a true 3d cursor. The 2d mouse movements are bound to either the x-y, x-z, or y-z movements of the 3d cursor. The cursor allows me to precisely pick or place points. The camera is moved around by simple controls:
a: forward
z: backward
up/down: pitch
left/right: turning
w/e: roll

These key binding are almost identical to the game Descent. I am not using quaternions to achieve these rotations, and the camera does not suffer from gimbal lock no matter what angle it is positioned at. I am using my own method of incremental vector rotation.

(c) Copyright 2003 Mark W. Sherman, all rights reserved.