» Mon Dec 20, 2010 10:05 pm
At first I was just gonna say the problem is that the HavokMaterial value names (such as HAV_MAT_STONE) aren't necessarily descriptive of the collision sounds they produce. This is true for some of them, but in your case there's something more going on which I didn't realize before.
I took a quick look in NifSkope at a few meshes that produce either metal-like or stone-like sounds, and found that both of them use HAV_MAT_STONE as the HavokMaterial. For example, look at Architecture\Megaton\interior\ShackInteriors\ShackWallLng01.nif (used in the Megaton Player House and others) and Architecture\Urban\Sidewalk\SWDoubleEdge01.nif (a sidewalk section used many places).
Ah, I think I found it! In NifSkope, expand the bhkRigidBody node. If it contains a bhkMoppBvTreeShape node (possibly other types), expand that further until you reach the hkPackedNiTriStripsData child node. Look in the Block Details for that node and fully expand any Sub Shapes there. Each Sub Shape has a Material assigned, which apparently overrides anything assigned to the parent bhkRigidBody node.
I just figured this out by looking at the Architecture\Wasteland\GasStation01.nif mesh, which produces different footstep sounds depending on which parts of it you might be walking over.