From BlenderWiki

[[{{{2}}}|      ]]>

[[{{{3}}}|      ]]>

Blender Summer of Documentation: Contents | Manual | Blender Version 2.42

[edit] The Linear Curve Tracking Spine

The spheres in this image are bones with a sphere mesh object given as the custom draw type.

This rig is a great alternative to the bones-on-curve system.

[edit] Let's Build It

I'm sure you could build this rig in a curved shape to match a curved model, but you're much, much better off saving yourself the trouble and making the model straight to begin with.

Add an armature and clear its rotation. Make a bone 8 units long, lying on the Y axis. All of the deform bones will come from this bone. Subdivide it four times using W->Subdivide Multi in Edit Mode.

Select all of these bones, duplicate them, and move them 5 units up on the Z axis. These duplicates are rig elements, not deform bones. If you want to give names, name the deform bones spine1 - spine16, and name the rig elements spineIK1 - spineIK16. I will use these names here, but it only matters that you understand which bones I'm refering to.

Add a new bone at the root of the lower chain. Name this bone CP1 (for Control Point). Create duplicates and place them as shown. Name these CP2 - CP6. Make each of the shown selected bones the child of the closest CP bone. Also make spine1 the child of CP1.

IK constrain each spine bone to it's spineIK duplicate. Change the IK constraint ChainLen value to 1 for each spine bone.

Give each of the shown selected bones Stretch To constraints, targeting the closest CP bone that they point to (e.g. spineIK1 targets CP3).

NOTE: Add the constraints in Pose Mode. When you first add the constraint, there will be a field for the object name, OB. Enter the name of the armature. Then a field for the bone name will appear, BO. Put the name of the bone in this field.

In edit mode, move all of the shown selected bones down and over, as shown.

[edit] Locking Things Up

Final steps: Lock the appropriate axes of the bones, and organize your layers.

[edit] This Rig in Review

Now lets consider the benefits and drawbacks of this design.

[edit] The Pros

• Very flexible.
• Allows for as many or as few spine bones as you need.
• Works without the use of outside objects, unlike bones on a curve.

[edit] The Cons

• Control inputs are tied to a specific section of the spine, so the spine is not automatically made smooth.

--Wavez 01:23, 17 July 2006 (CEST)

Tutorials

Redirects to fix

• BSoD/Introduction to Rigging/Making a Spine Twist → Doc:Tutorials/Animation/Armatures/BSoD/Making a Spine Twist
• BSoD/Introduction to Rigging/The Bones-on-Curve Spine → Doc:Tutorials/Animation/Armatures/BSoD/The Bones-on-Curve Spine
• Blender Summer of Documentation → BSoD
• Manual/Manual → Manual