Properties of bones, rotated with controlbones..?

Hey all,

I finally start to understand how rigging works, and am making great progress on the rig for my character although it’s not good yet… but it starts working.

Now I wanted to try out a technique for fixing deformation on joints, with lattices. But for that I’ll need to make shapekeys on that lattice, driven by the rotation of for example the neck-bone.

This neck-bone is rotated following the location of a controlbone, I called it Ctrl.Head.

To make the driver for the shapekey, I need to know what the rotation of the neckbone is, but when I move the neck, using the Ctrl.Head - bone, the properties of the neck-bone don’t change…

How then can I find the information about the rotation of the neck-bone?

I would want to use these property-values to limit the possible rotation of these bones too, because my head does not need to turn 180°.

If my way of working is wrong, let me know…

First, “Prorerties” in blenderspeak are a GameEngine doodat, but I think I know what you mean. Second, you can leave out the Lattice (you don’t have to) and use a Shape on the verts of the neck directly.

If the NeckBone runs parallel to the spine (as it should) then you select the Rot-Y IPO in Pose Context in the IPO Window and add a Driver to that. Fill in the name of the Armature, then the name of the Bone (Ctrl.Head) and select the Rot-Axis that Ctrl.Head will rotate to drive the neck bone.

Then you select the Shape IPO in Shape Context in the IPO Window and put a Driver on that with the name of the neck bone and the Rot-Y axis (same procedure as above).


I’ll try that out next thing in the morning, thanx alot


I tried it, but it did not work… If I try to add a driver to the neck-bone, and type in the name of the armature, it says I can’t use the same armature as driver for the neck-bone, and the Ctrl.Head bone, is from the same armature ofcourse…

Thanx for the idea ofcours, Fligh… If it works for you it should work for me too.


The driver is applied to the mesh (which is where the shape key is set … you can’t set a shape key on a bone/armature), with the driver Ob:(ject) being the Armature/bone. I.E. select your mesh, change the IPO curve types to Shape, select the particular shape key from the list on the right of the IPO window, press N to bring up the properties … etc.


Yes, The bone Ctrl.Head must be in an Armature seperate from the Armature that has the neck bone.


So, in short, I need an armature to define the deformation of the mesh in movements, and a different armature to control the first one?

In all tutorials I’ve seen that hasn’t been mentioned yet. I haven’t found anything like that in the files from the DVD I bought of Elephants Dream either…

I’m getting more and more confused about the subject ‘rigging’.

Haha, the search continues…


A second armature is only needed when using an IPO driver, as an IPO driver object cannot drive itself (the Armature being the object, all bones are still part of that object).

Apparently if you use PyDrivers (a Python driver) this limitation does not exist …according to the release notes anyway. How you’d code the expression / Python code is another thing :slight_smile: … Probably be faster to just create that second armature :slight_smile:

“For now pydrivers can reference their own object, something normal
ipodrivers can’t. This seems to work fine and is quite useful, but if
tests prove the restriction is necessary, we just need to uncomment a
piece of code in EXPP_interface.c, marked with “XXX”.”