BND
BND is a simple ASCII format file used to define the collision box of an object. An example of a BND file would be this:
<td>version: 1.01 verts: 12 materials: 1 edges: 0 polys: 13
v -1.237810 0.624240 2.996410 v -1.237810 1.771920 2.827500 v -1.237810 2.202820 -0.881580 v -1.237810 1.310590 -2.904570 v -1.237810 0.420690 -2.904570 v 1.243870 0.624240 2.996410 v 1.243870 0.420690 -2.904570 v 1.243870 1.310590 -2.904570 v 1.243870 2.202820 -0.881580 v 1.243870 1.792910 2.827500 v -1.237810 2.192200 1.307540 v 1.243870 2.192200 1.307540
mtl default { elasticity: 0.100000 friction: 0.500000 effect: none sound: 0 }
quad 0 1 2 3 0
tri 3 4 0 0
quad 5 6 7 8 0
quad 11 9 5 8 0
quad 0 4 6 5 0
quad 4 3 7 6 0
quad 2 10 11 8 0
tri 1 0 5 0
tri 5 9 1 0
quad 8 7 3 2 0
tri 9 11 10 0
tri 10 1 9 0
tri 1 10 2 0
</td>
BND's can have their own materials (grass, cobblestone, etc.) depending on what the purpose of the BND is (car's collision box, drivable surfaces, etc.)