What exactly is an isosurface?????

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Saadat Saeed wrote:
> 
> What exactly is an isosurface?????

In mathematical terms it's the equipotential surface of a 3d function f(x,
y, z)

Not sure if that helps you much. :-)

followup to p.u.p.

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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Saadat Saeed <saa### [at] hotmailcom> wrote:
: What exactly is an isosurface?????

  As Christoph already answered, is the equipotential surface of a function
f(x,y,z).

  What does this mean?
  This means that the isosurface is an object with the following properties:
  1. A point <x,y,z> is outside the object if the value of f at that point
     is larger than a certain (constant) value 'n'.
  2. A point <x,y,z> is inside the object if the value of f at that point
     is smaller than 'n'.
  3. A point <x,y,z> is exactly at the surface of the object if the value
     of f at that point is exactly 'n'.

  In other words, the isosurface is a surface in space where the function f
has the same value at each point.
  It's the same principle as in isobar lines (the air pressure is the same
along the line) or height lines in a height map (the height of the ground
is the same along the line), but with a surface instead of a line.

  f(x,y,z) can be any mathematical function.

  Example: To get a spherical surface, define:

  f(x,y,z) = sqrt(x*x+y*y+z*z)

with 'n' being the radius of the sphere.

  (sqrt(x*x+y*y+z*z) is actually the distance of the point <x,y,z> to the
origin.)

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

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