[Radiance-general] obj2rad failing

[Erwin Zierler]

Hi all,

I am currently testing differrent converters with what you could call 'real-world' scene files originating from differrent CAD systems and modellers. While exploring the capabilities of obj2rad I noticed that it fails on a OBJ File (exported from ArchiCAD) with the following error:

example.obj: Wavefront syntax error near line 167037: Bad face

Here is the 'bad' part of the file (line 167037 - 167041)

f  29760/83929/29760 29761/83930/29761 29762/83931/29762 29763/83932/29763
vt 42.5353 8.46865
vt 42.5353 8.474
vt 42.53 8.474
vt 42.53 8.469

Other parts of the obj file work fine:

f  29682/83789 29683/83790 29684/83791 29685/83792
vt -0.019984 -0.400179
vt 8.56333 -0.400179
vt 8.58332 0
vt 0 0

The OBJ file format specification tells me that both 'f' lines are perfectly legal:

Using v, vt, and vn to represent geometric vertices, texture vertices,
and vertex normals, the statement would read:

    f v/vt/vn v/vt/vn v/vt/vn v/vt/vn

But obj2rad doesn't seem to like the 3rd number(s) vn which are supposed to represent the vertex normals. The obj2rad man page doesn't go into much detail about the 'f' statement with respect to allowed format. Running obj2rad -f (ignoring vertex normal information) also fails on the exact same line. 

I will try to get ahold of some smaller ArchiCAD OBJ exports now and see if I can narrow down the problem. If anyone has some ideas or similar experiences I would sure appreciate to hear from you!
TIA,
 Erwin