FABRIK Root

Multi-effector FABRIK system.
FABRIKRoot is a component that connects FABRIK chains together to form extremely complicated IK systems with multiple branches, end-effectors and rotation limits.

Getting started:

• Create multiple FABRIK chains, position them as you want them to be connected. The chains don't have to be parented to each other
• Make sure the first bone of a child chain is in the same position as the last bone of its parent
• Create a new GameObject, add the FABRIKRoot component
• Add all the FABRIK chains to "Chains" in the FABRIKRoot component
• Press Play

Accessing the chains of FABRIKRoot:

public FABRIKRoot fabrikRoot;

void LateUpdate () {
    Debug.Log(fabrikRoot.solver.chains[index].ik.name);
}

Limitations:

• Separate FABRIK chains can not use the same bones, they must be fully independent
• The last bone of a FABRIK chain must be in the same position as its child chain's first bone

FABRIK Root chain being pulled

Component variables:

• fixTransforms - if true, will fix all the Transforms used by the solver to their initial state in each Update. This prevents potential problems with unanimated bones and animator culling with a small cost of performance

Solver variables:

• weight - the solver weight for smoothly blending out the effect of the IK
• iterations - max iterations per frame.
• rootPin - the weight of pinning the first chains to the Transform that the component is attached to
• chains - the list of FABRIK components used by this FABRIKRoot

Chain variables:

• IK - the FABRIK component used
• pull - parent pull weight. How much does this chain pull its parent?
• pin - resistance to being pulled by child chains. If 1, this chain can not be pulled out of place by its child chains
• children - indexes (of the "Chains" array) of the direct children of this chain. Don't add children of the children.