Let me try to explain what I’m trying to do a little better.
I want to be able to animate various parts of the gun, while animating the arms. For example, a handgun has the guy pull the action back by pulling the top of the gun. Where as a rifle may pull the action back via a slide on the side of the gun. Those parts should be animated, and the arm/hand animations should be in sync with the gun animations. The only way I can see doing this is to animate them together.
I did a simple test where I created a cube with a bone, and did a simple movement animation. I then added a second mesh, a cylinder with it’s own bone. I parented the cylinder bone to the cube bone, to mimic the gun handle being parented to the hands. When I did this in Blender, the cylinder automatically inherited the animations from the cube. I exported the objects separately, then imported them into Unreal. I attached the cylinder to a socket I placed on the cube’s bone. When I play the animation on the cube, it works as expected…the cylinder follows the socket on the cube. However when I play an animation on the cylinder and the cube, the animations are additive so the cylinder floats off away from the cube.
This means that I can’t parent the weapon to the arms without the animations getting all wacky. I guess I basically have to place the socket for the weapon in the middle, not attach it to any bones, and just let the animations take care of the alignment. In my cube and cylinder test I detached the socket from the bone, changed the cylinder’s bone from “Animation” to “Skeletal” and the animations aligned how I expected them. My next worry from there is hopefully this doesn’t cause problems when I rotate the meshes to follow the rotation of the camera. I’m guessing as long as I rotate the socket along with the arm mesh, it will continue to align as expected?