Marching Cubes - Cal Poly CSC 471
by
Erik Toraason
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This is a marching cube project that I did for my CPE 471
graphics class. In it I take the implicit equation of a surface and
apply the equation to a grid of cubes. Based on the position of each
edge on each cube you can decide if it lies inside or outside of the
surface. Basically an isovalue is computed so that anything less than 0
would be inside the surface and anything above 0 would be outside the
surface. Based on these isovalues, if the values of all eight corners
are not the same than obviously the surface cut through the cube. From
here, a meash of triangles is made to represent the surface of
intersection. Putting all these triangles together gives a
representation of the implicit surface. I added flat shading which
involves computing the normals per face. Also, I have a cube mode which
allows the user to see aech of the cubes drawn without any slices made
into the cube. I have a light source that has a couple of materials and
a virtual trackball to rotate the object. There are 4 possible implicit
equations that are included and each one can be shown as filled or
wireframe.
The tables I used as well as many of the ideas and some of the code in
the algorithm are from Paul Bourke who is an accredited programmer,
whose work on marching cubes can be found all over online. http://local.wasp.uwa.edu.au/~pbourke/geometry/polygonise/
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The instructions are quite simple. They are:
- "w" to
switch between wireframe and filled
- "m" to switch between regular cube mode
and marching cube mode
- "c" to switch materials
- "l" to toggle
the light
- "r" to turn on the trackball
- "q" to quit
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