STLA_TO_TRI_SURFACE is a MATLAB program which reads data from an ASCII STLA file describing a triangular mesh of a 3D surface, and converts it to a pair of arrays describing a triangular mesh or TRI_SURFACE.
Especially if you are reading large ASCII STL files, you might want to consider the "fast" version of the program, which uses the routines STLA_SIZE_FAST and STLA_READ_FAST, provided by Bill Seufzer of NASA Langley.
An ASCII STL file contains a description of the surface of a solid that has been decomposed into triangles. The vertices of the triangles should be listed in counterclockwise order, as viewed from outside the surface. A normal vector for the triangle may also be listed.
A TRI_SURFACE or triangulated mesh surface, is described by a pair of arrays:
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
STLA_TO_TRI_SURFACE is available in a MATLAB version.
OBJ_TO_TRI_SURFACE, a MATLAB program which reads an OBJ file and extracts the surface mesh data as a TRI_SURFACE dataset.
PLY_TO_TRI_SURFACE, a MATLAB program which reads a PLY file and extracts the surface mesh data as a TRI_SURFACE dataset.
STLA, a data directory which contains a description and examples of STLA files.
STLA_DISPLAY, a MATLAB program which reads an ASCII STL file and displays it.
STLA_IO, a MATLAB library which reads or writes a PLY file.
STLA_TO_TRI_SURFACE_FAST, a MATLAB program which is a faster version of stla_to_tri_surface.
TRI_SURFACE, a data directory which contains examples of TRI_SURFACE files.
TRI_SURFACE_DISPLAY, a MATLAB program which displays a TRI_SURFACE dataset.
TRI_SURFACE_IO, a MATLAB library which reads and writes the 3D graphics information in a TRI_SURFACE file;
TRI_SURFACE_TO_PLY, a MATLAB program which converts TRI_SURFACE data to data suitable for storage as a PLY file.
TRI_SURFACE_TO_STLA, a MATLAB program which reads a TRI_SURFACE dataset and extracts the surface mesh data as an ASCII STL file.
CUBE is a cube using 12 triangular faces and 36 nodes.
MAGNOLIA is a magnolia blossom, using 1247 triangular faces and 3741 nodes.
You can go up one level to the MATLAB source codes.