holopy3/Assets/Plugins/RootMotion/FinalIK/Tools/ShoulderRotator.cs

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2020-12-10 14:25:12 +00:00
using UnityEngine;
using System.Collections;
using RootMotion.FinalIK;
namespace RootMotion.FinalIK {
/// <summary>
/// Shoulder rotator is a workaround for FBBIK not rotating the shoulder bones when pulled by hands.
/// It get's the job done if you need it, but will take 2 solving iterations.
/// </summary>
public class ShoulderRotator : MonoBehaviour {
[Tooltip("Weight of shoulder rotation")]
public float weight = 1.5f;
[Tooltip("The greater the offset, the sooner the shoulder will start rotating")]
public float offset = 0.2f;
private FullBodyBipedIK ik;
private bool skip;
void Start() {
ik = GetComponent<FullBodyBipedIK>();
// You can use just LateUpdate, but note that it doesn't work when you have animatePhysics turned on for the character.
ik.solver.OnPostUpdate += RotateShoulders;
}
private void RotateShoulders () {
if (ik == null) return;
if (ik.solver.IKPositionWeight <= 0f) return;
// Skipping the second update cycle
if (skip) {
skip = false;
return;
}
RotateShoulder(FullBodyBipedChain.LeftArm, weight, offset); // Rotate the left shoulder
RotateShoulder(FullBodyBipedChain.RightArm, weight, offset); // Rotate the right shoulder
skip = true;
ik.solver.Update(); // Update FBBIK again with the rotated shoulders
}
// Rotates a shoulder of a FBBIK character
private void RotateShoulder(FullBodyBipedChain chain, float weight, float offset) {
// Get FromToRotation from the current swing direction of the shoulder to the IK target direction
Quaternion fromTo = Quaternion.FromToRotation(GetParentBoneMap(chain).swingDirection, ik.solver.GetEndEffector(chain).position - GetParentBoneMap(chain).transform.position);
// Direction to the IK target
Vector3 toTarget = ik.solver.GetEndEffector(chain).position - ik.solver.GetLimbMapping(chain).bone1.position;
// Length of the limb
float limbLength = ik.solver.GetChain(chain).nodes[0].length + ik.solver.GetChain(chain).nodes[1].length;
// Divide IK Target direction magnitude by limb length to know how much the limb is being pulled
float delta = (toTarget.magnitude / limbLength) - 1f + offset;
delta = Mathf.Clamp(delta * weight, 0f, 1f);
// Calculate the rotation offset for the shoulder
Quaternion rotationOffset = Quaternion.Lerp(Quaternion.identity, fromTo, delta * ik.solver.GetEndEffector(chain).positionWeight * ik.solver.IKPositionWeight);
// Rotate the shoulder
ik.solver.GetLimbMapping(chain).parentBone.rotation = rotationOffset * ik.solver.GetLimbMapping(chain).parentBone.rotation;
}
// Get the shoulder BoneMap
private IKMapping.BoneMap GetParentBoneMap(FullBodyBipedChain chain) {
return ik.solver.GetLimbMapping(chain).GetBoneMap(IKMappingLimb.BoneMapType.Parent);
}
// Remove the delegate when destroyed
void OnDestroy() {
if (ik != null) ik.solver.OnPostUpdate -= RotateShoulders;
}
}
}