View Full Version : Parallel BlendShape for the Elbow

03 March 2007, 06:20 PM
Hi everyone!
I don't understand the reason why this happens, thank you in advance for any helps:

This is a simple rigged and skinned character with an FK setup for the Arm.
(copy and paste the link on the address window to see the images)

I've applied a BlendShape and a Set Driven Key in the way that when the elbow rotates, the bicep muscle expands (the blendshape value switch from 0 to 1), and the elbow area doesn't lose volume.

The problem arrives when I rotate the shoulder (or any other spine or hip bones) forward and backward (also up and down)

You can see that the elbow area continues to deform also if the rotation value of the Elbow_joint remains fixed.

I have to say that creating the BlendShape I've used a "Parallel" Deformation Order, and maybe this could be the reason, I don't know; I've tried using a "Front of Chain", and it seems to work better, but I've to deform the target geometry in a strange way to obtein good result.

Anyway. Any explenation or advice will be well accepted.

03 March 2007, 02:41 AM
hey Ossosso

I have run into the same problem when using a SDKs to drive corrective shapes, I have hadsome success with expressions, they will slow your rig a bite but they work.

I am also trying a new method where you create a cluster with smooth interpolation and its scale driven by util nodes. A tip from theazz (

Also you could try poseDeformer by Mike Comet (, I have had victory with this is the great


03 March 2007, 10:57 AM
Thank you very much Captain Boom

For the moment I've "reparied" using a "Front of Chain" BlendShape with an "Inbetween".
It isn't so precise but, oh my God... I've started the whole realization from the beginning (modeling, skin, rig, textureing, blendshape), and the path has been full of obstacles; I'm tired to turn back on my steps and "repair"... for this time I've accepted a compromise with Maya :).

Anyway I've downloaded the PoseDeformer plugin (I've not understood really well how it works yet, but I'll study it better) and it seems similar to my "UVDriver" setup: for each shoulder direction of rotation (Up, down, forward, backward) corresponds e BlendShape (Parallel), and they are blend together, in the sense that if I rotate the shoulder Up\Forward maya uses both the blendShape in a certain percentage.

Anyway I thank you very much, the "comet-cartoon" site seems really useful, I didn't know.


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03 March 2007, 10:57 AM
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