obj - convert polygons to triangles

[blogdron]

Many 3D editors create polygons instead of triangles by default. And convert each model is inconvenient. And if this is not done, the models are painted without half surfaces. When rendering, only triangles are used, so it seems to me to be good if the polygons are automatically converted into triangles.

• Test model is default blender monkey (Export without model triangulation)

Test model before edit obj_load_file()

Test model after edit obj_load_file()

I found a conversion mechanism here https://stackoverflow.com/questions/23723993/converting-quadriladerals-in-an-obj-file-into-triangles I hope everything is correct and it will not cause hidden bugs, but I kind of checked on different export files, everything seems to be fine.

[blogdron]

i found bug for 12 elems like f 1/1/1 2/2/1 3/3/1 4/4/1 i close now and going fix it