I'm working on a model to be exported into a game, but I'm having some trouble with it. I created an Empty type object, which I'm using as a "tag" for the mesh. The game engine will use these to attach other models/objects to this one (e.g., putting weapons in my model's hands).
So I created the Empty object, put it where I wanted it, and parented it to the bone of my choice. The export seems to have worked perfectly, but I went in to adjust the object's position and direction slightly, and some crazy things have happened. First of all, it's way off of where it should be, second of all, the entire armature seems to have been transformed when I reopened the blender file. How in the world would a transformation to a child object effect the parent? In looking at the Blender data structures, it seems that the object is not parented to the bone at all, but to the bone's parent armature. Consequently, the empty's local matrix is relative only to the armature, and I'm not sure how to derive a matrix relative only to the joint. The whole data structure seems badly organized, and I'd like help with any or all of these problems, in whatever way you can provide.
--D. Scott Nettleton