Function obj = wobj_read_simple(fn)
reads vertex and face information from a simple (!) .obj
file. An .obj file is a three-dimensional geometry definition
file format first developed by Wavefront Technologies.
It is assumed that:
-- each vertex is defined as
"v <x> <y> <z>"
on a line, where "<x>", "<y>" and "<z>" are text
representations of reals for the x,y,z coordinates.
-- each face is defined as
"f <iv1> <iv2> <iv3>"
on a line, where "<iv1>", "<iv2>" and "<iv3>" are the
indices to the vertices (the first vertex has index 1),
which make a triangle. Other types of polygons are not
allowed.
Other information in the file is ignored.
The function internally calls perl with the external scripts
"wobj_extract_vertices.pl" and "wobj_extract_faces.pl", which
must be somewhere in the current directory or the Octave load
path.
The output is a struct with two fields:
obj.vertices contains a matrix with three columns;
obj.faces contains a matrix with three columns.
(c) 2026 fabien van mook
2026.08.20 release of this file within package "fvm-geometry-obj" under GNU GPLv3+
