For like a several years I'm messing up with 3D and I've wrote my own OBJ loader. When I looked at Assimp's OBJ loader i fugure out a lack of just a few features/compatibilities.
1. Normal maps with map_Kn map_Bump ( another than map_bump ) - some exporters seems to tag normal textures this way
2. Vertex/UV/Normal indexing normaly looks like
f 12/1/4 . . . etc.
There are exporters that uses non global space of indexes ( starting with 1 , and the index is static and global for the rest of the obj file ). I met obj's that have face looks like :
f -4/-2/-3 . . . etc
Negative numbers tells us Xth index behind the f. For example :
v .. //fisrt
v .. //second
v .. //third
f -1/-2/-3 // face with vertices : third / second / first
I'd be nice if you guys could add these two more things. You made great work with Assimp ;)
thanks for the hints, I haven't know them. I will update the obj-importer to support these features as well ( the material statements may be finished faster :-) ).
I just pushed the stuff for the normal map support. The negativeindex support will be my next task for the asimp library. You can find the changes at github.
Its good to hear it :)