You aren’t limited to the built-in Sample Spaces. To make your own space, create a plain text file containing a list of 4×4 matrices generating the space’s group of covering transformations. See, for example, the built-in files for

- the 3-torus,
- the Poincaré dodecahedral space, and
- the mirrored right-angled dodecahedron.

Curved Spaces uses the *(row vector)(matrix)* convention
rather than the *(matrix)(column vector)* convention,
so the matrices may be the transposes of what you were expecting.
In the spherical case this makes no difference because the transpose
equals the inverse, but in the flat and hyperbolic cases it’s
important to get it right.

Let your text editor save your 4×4 matrices as a plain *.txt* file,
then manually change the filename extension to *.gen*.

*Macintosh:* This assigns the Curved Spaces icon, which you may
double-click to open the file in Curved Spaces.

*Windows:* To open the file, choose Open from within Curved Spaces.

Curved Spaces 3.0 includes a smaller, more streamlined library than Curved Spaces 1.0 had. The omitted spaces are available upon request.