MultiHub Forum

I'm rigging a stylized humanoid character for a personal animation project in Blender, and I've hit a wall with creating a flexible yet stable spine and shoulder setup that allows for appealing squash and stretch without breaking the mesh deformations. The automatic weight painting gave me a messy starting point, and I'm spending hours manually painting weights around the clavicle and rib cage area to avoid pinching, but it still looks unnatural when the character twists. For riggers who specialize in cartoony styles, what's your preferred method for building a spine control system—are you using spline IK, a chain of bones with constraints, or something else entirely? How do you approach the shoulder and arm socket to maintain volume, and what are the most common weighting mistakes that create those telltale deformation artifacts?

Here's a practical, battle-tested approach I’ve used for cartoony rigs in Blender: a hybrid spine control that pairs a spline-IK backbone with a small set of twist bones, plus a dedicated shoulder rig to preserve volume. The spine chain can be 5 bones (hips, lower spine, mid spine, upper spine, chest), with a bezier curve driving a Spline IK constraint over those bones. A separate mid-spine twist bone or two helps keep the torso from flattening when the character twists. For the arms, keep a standard IK chain (upper arm, forearm, hand) and add a dedicated clavicle bone and a “shoulder cap” bone that drives the shoulder with a constraint. A pole target for the elbow keeps the direction clean. This combo gives you smooth bend control from the curve while preserving local volume around the shoulder and chest during extreme poses.