. If i divide an interval in 20 steps, i end up with 21 numbers, so i'm creating a grid of points that consists of 21 x 21 points. Since the surface component asks for the number of points in the U direction, i get the number "20" and add 1 to end up with 21.
If you want to create an isosurface, it's not as easy since the points can't be arranged into a grid. You can display the boundary points of the surface easily but to create actual geometry you need something like a marching cubes algorithm. I did a definition for it but it works really slow. An alternative can be to bake the points and use rhino's mesh from points command.…
Added by Vicente Soler at 1:22pm on November 30, 2009
Grasshopper 3D all versions before 2011 are available for download on ARTC.it.
For all of you Grasshopper maniacs, there's also the very first idea of Grasshopper: Explicit History (Jan 31, 2008).