[3D Studio Max] Rigging a weapon

Questions & Answers
1

I have trouble rigging my weapon. I have a shotgun model with a skin modifier that has two bones: one dummy object that moves the vertices of the charging handle part of the mesh, and one root bone that doesn’T control any vertices.

Both the dummy bone and the mesh itself have the root bone as their parent.

Inside Max the animation (the dummy, and therefore the charging handle, rocks back and forth) looks good.

However, when I export the model to FBX and use it in Unity, there seems to be something wrong, maybe with the hierarchy. In any case, when I play the animation inside Unity the whole mesh is moved.

The hierarchy inside Unity looks like this:

Shotgun (has Animation)
-Root Bone
 -Dummy (charging handle bone)
 -Shotgun Mesh (with skinned mesh renderer)

How do I set up my model the right way?

2

I found the solution after comparing it to a fully rigged character model that works flawlessly.

The hierarchy inside Max has to be as follows:

Root Bone
-Dummy (charging handle bone)

The Shotgun mesh itself is onyl connected to the bones via the skin modifier that includes both bones. The important part is that EVERY vertice of the model has to be affected by at least one bone. Before, I only had the charging handle vertices affected (by the dummy), and nothing else. Now I made all other vertices being affected by the root bone and voilá, it works at it should.

Hope this helps should someone have the same problem.