Loft objects are created with a number of flat cross-sections parallel to the floor. Boxshot connects them one by one, making a contour of the shape. You can move cross-sections (called “layers”), adjust if they edges are hard or soft, set if connections are flat or curvy and so on. Boxshot comes with a set of sample loft objects, so you can have a look at what can be done.
You can read more about creating loft objects here.
When you create a loft object, you get just two options in its properties panel:
Loft objects can have multiple materials, defined in loft editor. Boxshot checks if two adjacent loft segments have similar material names and joins them together, generating shared UV mapping.
Loft objects are too complex for scripting, so all you can control is the left of details:
var m = scene.root.addMesh("loft", "generator.loft"); var g = m.generator; g.lod = 0.8;
The rest is better done using loft editor window.