[Radiance-general] filtering normal information from an obj

[Lars O. Grobe]

Hi!

As obj2mesh doesn't support something as obj2rad's -f option to filter 
surface normal information, and mgffilt cannot be used here because 
native radiance-format is not involved using obj2mesh (well, I could use 
obj2rad -f and than the new rad-to-obj filter, but that does not seam to 
make sense to me with all my large files), I wonder how people get rid 
of normals if needed.

I started with grep -v "vn", but that only removes the vertices, not 
their referneces in the face (f) lines. So I need a sed-command maybe, 
that finds the normal vertex reference by examining the /-seperated 
triples in lines beginning with f and replace the normal vertex index by 
0. And it should take care of lines that are continued after a line 
break, indicated by a backslash, as that seams to be valid in obj.

I am not very good in sed. If someone has a tested sed-string (I guess 
so) it would be great if you could post it, might be of general 
interest. If not, I will have to think myself ;-) and make hundreds of 
failed attempts to get this done...

Thanks... Lars.