how to create high quality .obj files

when i imported one of my works link-
https://grabcad.com/library/bmw-logo-3d-model-not-decal-1/files/bmw%20logo.obj

to unity 3d it l had lots of gap in between.snapshot added
could anyone help me to figure out possible cause
i used solidworks 2011 to make this model and exported as obj

thanks

1 Answer

Nurbs verses poloy lines. imagine a stl file, it uses pololines. converting one to the other is time consumeing.