Very good technique!

The presentation of it was maybe a bit hard to follow.

To summarize:

1. If you have geometry described by a function (as used by
an isosurface object), you can can render its boundary using
a constant thickness (as opposed to the entire solid object).

2. The technique is to difference two isosurface objects for
the same function using a slightly different threshold.

3. In order to achieve constant thickness the function needs to
be normalized by dividing through the length of its gradient.


In your examples, you used simple functions for which the
derivative could be calculated analytically. Maybe this could
also be done by a general macro that uses a gradient of

sqrt(((f(x+e,y,z)-f(x,y,z))/e)^2,
      ((f(x,y+e,z)-f(x,y,z))/e)^2,
      ((f(x,y,z+e)-f(x,y,z))/e)^2)

for some small value of e?

Post a reply to this message