Assign same z to a set of faces

Here the lattice modifier is your friend.
I started from a 16x15 sphere and applied a lattice modifier with 16 subdivisions along z.

Then I selected the control points four at time and lowered the corresponding slices down.

Here is the result:

Creating sculpties with Albatross3D

First of all you should have downloaded Albatross3d from the website http://www.ppmodeler.com. I've used the version for Windows published on Jun 2008.

Then you should get the exporter files and copy it in the scripts subdirectory of the Albatross installation directory.

Now start Albatross and create a sphere with longitude 32 and latitude 31 (see picture).



The exporter currently works with spheres 8x7, 16x15, 32x31 and 64x63.

Now modify your sphere moving the vertices and the faces or using the sculpting function or applying the modification tools (i.e. do not add or remove vertices).

The following picture shows the lattice modifier:



Now you simply export the model to a sculpty:



to obtain a 128x128 bitmap:



that you can upload into SL.