I'm using max 2015, but I believe it does it in other versions.
When importing a model that has bones with no vertex weights, the importer will auto assign weight to the nearest vertex (as max would normally do when adding a bone to the skin modifier). However, these vertexes that it's assigning weight to already have weight properly assigned to those verts.
This commonly happens for stuff like weapon bones, hat bones, and other stuff that gets $bonemerge'd in for player models. Would it be possible to make the exporter simply drop zero-weighted bones from the skin modifier (but still import them into the scene) ? This would likely be an easy fix for the problem.
This is somewhat unrelated:
Another thing that I've noticed is that the importer splits the mesh and smoothing groups wherever there are UV map seams. It's not a huge problem, but both the cannonfodder and wunderboy importers handled this fairly well using explicit normals or by rebuilding smoothing groups. Even when using your weld option, it still seems to occur. This is probably due mostly to models being decompiled, but it does still happen on exported/imported SMDs. It's not a huge problem anyways.
Attached is decompiled model that imports OK with the 2012 compiled max importers, but has trouble with the wall worm maxscript importer (due to 0 weighted bones). Stuff like prp_pouch, prp_hat, weapon_bone, etc should not ever have weight assignment.
When importing a model that has bones with no vertex weights, the importer will auto assign weight to the nearest vertex (as max would normally do when adding a bone to the skin modifier). However, these vertexes that it's assigning weight to already have weight properly assigned to those verts.
This commonly happens for stuff like weapon bones, hat bones, and other stuff that gets $bonemerge'd in for player models. Would it be possible to make the exporter simply drop zero-weighted bones from the skin modifier (but still import them into the scene) ? This would likely be an easy fix for the problem.
This is somewhat unrelated:
Another thing that I've noticed is that the importer splits the mesh and smoothing groups wherever there are UV map seams. It's not a huge problem, but both the cannonfodder and wunderboy importers handled this fairly well using explicit normals or by rebuilding smoothing groups. Even when using your weld option, it still seems to occur. This is probably due mostly to models being decompiled, but it does still happen on exported/imported SMDs. It's not a huge problem anyways.
Attached is decompiled model that imports OK with the 2012 compiled max importers, but has trouble with the wall worm maxscript importer (due to 0 weighted bones). Stuff like prp_pouch, prp_hat, weapon_bone, etc should not ever have weight assignment.