Trigonometric IK

Trigonometric IK is the most basic IK solver that is based on the Law of Cosines and solves a 3-segmented bone hierarchy. (IKSolverLimb extends IKSolverTrigonometric just to add a couple of extra parameters like the bend modifiers)

Getting started:

• Add the TrigonometricIK component to the first bone.
• Assign bone1, bone2 and bone3 in the TrigonometricIK component
• Press Play

Getting started with scripting:

public TrigonometricIK trig;

void LateUpdate () {
    // Changing the target position, rotation and weights
    trig.solver.IKPosition = something;
    trig.solver.IKRotation = something;
    trig.solver.IKPositionWeight = something;
    trig.solver.IKRotationWeight = something;

    trig.solver.SetBendGoalPosition(Vector goalPosition); // Sets the bend goal to a point in world space 
}

Adding TrigonometricIK in runtime:

• Add the TrigonometricIK component via script
• Call TrigonometricIK.solver.SetChain()

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:

• bone1 - the first bone (upper arm or thigh)
• bone2 - the second bone (forearm or calf)
• bone3 - the third bone (hand or foot)
• target - the target Transform. If assigned, solver IKPosition and IKRotation will be automatically set to the position of the target
• positionWeight - the weight of solving to the target position (IKPosition)
• rotationWeight - the weight of solving to the target rotation (IKRotation)
• bendNormal - normal of the plane defined by the positions of the bones. When the limb bends, the second bone will always be positioned somewhere on that plane

Script References:

• Solver
• Component