Center of Mass Problems

I am relatively new to Blender and have managed to bumble my way around to feel quite comfortable with the program but I have ran into a snag. I am attempting to animate a man running with a gun in his hands. To “pose” the gun I simply added another bone to the original rig and made it the child to his main hand. However, I find when I switch from edit mode to object mode and attempt to bind the gun and bone the bone is sent in apparently random directions/rotations. I was under the impression that a “child” bone goes through all the transformations/rotations of its parent and should therefore, be in the same position relative to its parent after any series of such transformations. Instead this thing is completely off and I am left scratching my head. I have attempted this procedure in several different ways but nothing seems to work. Does anybody have any suggestions?

I have been able to successfully get the animation to appear correct in blender, but when I export it to Cal3d the thing is still in its original off position.

bkocher3, it’s bad form to start two threads for exactly the same problem.

Quite often, the problem with apparently random rotations and such is caused by not resetting scale and rotation on the object prior to fitting it with a bone. The scale value acts as a multiplier (not a problem if it’s 1) and the rotation is added in, which doesn’t seem like it should cause problems, but it might when the combined rotations suggests to Blender that the shortest route to the total rotation is in the opposite direction to what you intended.

Ctrl+A is the hot key to “Apply Scale and Rotation” (Ie: set scale to 1 and rotation to 0) to an object in object mode.

Another problem that frequently occurs is when the center of the object is not the apparent center of the mesh. This happens when the entire mesh is selected and moved in edit mode, which doesn’t move the center of the object. Rotation and scale calculations are based on the object center. The Mesh panel has a couple of buttons, Center and Center New, which allow you to manipulate the center of the object automatically. You can also simply move the mesh in edit mode. Check out the tool tips: 'Object data" means the coordinates of the vertices that make up the object’s mesh.