SVX is a voxel file format for representing 3D printable objects.
It is much more efficient than triangle meshes for representing "lattice" like
shapes with lots of fine internal structure.
If your shape requires 100,000,000 triangles to represent, then you probably
can't 3D print it, because personal computers do not have the memory and
processing power to process such a large mesh. But in this kind of situation,
an SVX could be processed without difficulty.

The SVX format was created by Shapeways. It supports two common coordinate
systems. The Z-is-up coordinate system used by Curv and OpenSCAD is intended
for 3D printing. The Y-is-up coordinate system is common in computer graphics.

`svx.sh` outputs a Z-is-up SVX file.
`svy.sh` outputs a Y-is-up SVX file.

Shapeways.com accepts SVX files, but only in the Y-is-up format.