Simple wireframe format?

Question

I'm looking for a simple file format to use for wireframe models. I am aware of VRML, u3D, etc, but these seem heavyweight for my needs. My criterea are:

• Must have a clear spec. Either open or very well established/documented.
• I only need (want) simple models - vertices and edges. I don't want to handle faces or objects. If the format supports more, that's fine so long as I can ignore them.
• End-user tools are not a requirement, but would be great. If not, it must be human readable (and editable for simple models).
• It would be nice (but not necessary) to be able to annotate or at least label nodes.
• It shouldn't matter what language I'm using, but probable options are Java/C++ & OpenGL

Or am I just better writing vertices/edge lists to a text file and be done with it?

Answer 1

Wavefront OBJ is a very simple text file format for storing 3d models and it's supported by all 3d modeling applications (eg. maya, 3dsmax, lightwave) so you can export and import your models very easily.

You can read more and the specs here:

http://www.fileformat.info/format/wavefrontobj/

I would recommend against making your own file format. The Wavefront OBJ is as simple as it gets and well specified.

Here's an example of a 2x2 plane. v is for vertex coordinates, f for description of faces (which vertices are connected):

v -0.500000 -0.000000 0.500000
v 0.000000 -0.000000 0.500000
v 0.500000 -0.000000 0.500000
v -0.500000 0.000000 0.000000
v 0.000000 0.000000 0.000000
v 0.500000 0.000000 0.000000
v -0.500000 0.000000 -0.500000
v 0.000000 0.000000 -0.500000
v 0.500000 0.000000 -0.500000
v -0.500000 -0.000000 0.500000
v 0.000000 -0.000000 0.500000
v 0.500000 -0.000000 0.500000
v -0.500000 0.000000 0.000000
v 0.000000 0.000000 0.000000
v 0.500000 0.000000 0.000000
v -0.500000 0.000000 -0.500000
v 0.000000 0.000000 -0.500000
v 0.500000 0.000000 -0.500000
f 1/1 2/2 5/5 4/4
f 2/2 3/3 6/6 5/5
f 4/4 5/5 8/8 7/7
f 5/5 6/6 9/9 8/8
f 10/10 11/11 14/14 13/13
f 11/11 12/12 15/15 14/14
f 13/13 14/14 17/17 16/16
f 14/14 15/15 18/18 17/17