an .obj loader problem about engine

[leonsal]

A commit was done that fixes the errors when loading the models.
But the decoding of the models materials is not quite correct yet,
showing wrong colors and materials properties.

You can get better results if you import the models using Blender and
export again from Blender to obj or collada format.
Blender has solved the quirks of decoding the obj format and
when exporting follows the "standard" more closely.

A new standalone demo g3nview was created
to view external models.

[SavostinVladimir]

Hi. Now it works. Ok, I will use Blender.
Thank you!