I've managed to extract all the vertex and normals data properly although I'm kinda stuck on the UV map part at the moment. As I understand it the BLV format does not have 3 sided polygons, they can be 4 or more easily. So the UV maps on conversion (forgot to mention that part

Example:

Some texture coordinates are good and some are weirdly distorted or totally just stripes. When I triangulate the polygons as is expected by most 3D formats I can see where the distortions are:

I'm kinda new to all this 3D stuff, so I ask you guys for help. What am I doing wrong and how would I go about fixing this problem. Do I need to manually triangulate the polygons and calculate new UV coordinates before converting to another format?
Thanks

Edit: Nvm tried triangulating manually before conversion, still same distortion

Edit 2: Nevermind again
