Printing. Printer. Manufacturing. Workshop. D_shape. Fabbers.com > The StL Format. An StL file consists of a list of facet data.
Each facet is uniquely identified by a unit normal (a line perpendicular to the triangle and with a length of 1.0) and by three vertices (corners). The normal and each vertex are specified by three coordinates each, so there is a total of 12 numbers stored for each facet. Facet orientation. The facets define the surface of a 3-dimensional object. As such, each facet is part of the boundary between the interior and the exterior of the object. 3form.