The next thing to do is to actually attach the skeleton to the mesh. To
do this, select all the vertices (Edit -> Select All) and select
Skeleton -> Bind Points to Skeleton. You will be prompted for a value for IK Weight Blending. IK stands for Inverse Kinematics and refers to the way that the bones towards the root end of the bone automatically follow bones further up the chain. IK Weight Blending defines the way that vertices are anchored to bones. See the tutorial on triangle meshes and the manual for more details of this. The default value of 0.5 will probably be OK as a starting point so accept this. >From now on, if you move the skeleton, the mesh will move along with it. Try it - save the file first, then activate the skeleton tool by clicking on the skeleton icon. Click on the endpoint of a bone and drag it. The mesh will follow the bone. However you may notice a problem - there is no control over where the bones are going. We need to restrict the bones' movement to produce a more realistic and controllable skeleton. |
Let's start with the first finger again. Click on the bone end at the fingertip to select it and select
Skeleton -> Edit Bone . This will bring up the dialogue box shown on the right: There are 4 main parameters here that can be controlled: X-bend, Y-bend, Twist and Length. The X-bend and Y-bend control the way the bone rotates about the joint at the root end of the bone (the narrower end of the 'kite'), i.e. they affect the side to side and back to front movements. The Twist parameter is effectively the z-bend in that in controls 'spin' around the joint. The last parameter, Length allows the bone to stretch or compress along its length. Note that both Twist and Length have the Lock option ticked by default. This means that these operations are prohibited. To enable them, simply untick the boxes. However, since fingers cannot twist or lengthen, we'll leave them as they are. Now, I don't know about your hand, but the first 2 joints in my fingers do not allow any sideways movement (X-bend), only movement backwards and forwards (Y-bend). So, click on the Lock tickbox to lock the X-bend. Now onto the backwards and forwards movement: The bone in the tip of my fingers doesn't bend very readily until the finger is curled right over at which point it can bend through about 90 degrees with respect to the next bone. There is no movement at all in the reverse direction. So, under the Y-Bend click on Restrict Total Range and enter the values 0 (for no backward movement) and 90 (for 90 degree forward motion). Because this movement doesn't occur until the finger is curled over, I suggest putting a Stiffness value in as well - say 0.5. |