public static void SolveIK(ref IKSegment segA, ref IKSegment segB, float x, float y, IKSettings settings)
{
var c2 = segA.length;
var c3 = segB.length;
var maxExtents = c2 + c3;
var c1Raw = Math.PythagorasC(x, y);
//if c1 raw is greater than c2 + c3, segment is out of range
var c1Max = Mathf.Min(c2 + c3, c1Raw);
//clamp max length by scalar of max extents
var c1 = Mathf.Clamp(c1Max, maxExtents * settings.extentsLimits.x, maxExtents * settings.extentsLimits.y);
var b1 = Math.TrigToaTheta(x, y);
var b4 = Math.LawOfCosinesABC(c2, c3, c1);
var a4 = Math.LawOfSinesA(c2, c3, b4);
var c4 = Math.PI - a4 - b4;
//b2 is adjacent to b4
var b2 = b1 - b4;
var b3 = Math.PI - c4;
segA.SetPointBFromAngle(b2);
segB.pointA = segA.pointB;
//world angle for segB
segB.SetPointBFromAngle(b2 + b3);
// Debug.Log($"ik debug: c1: {c1.ToString("0.0")}\tb1: {b1.ToString("0.0")}\tb2: {b2.ToString("0.0")}\tb3: {b3.ToString("0.0")}\tb4 :{b4.ToString("0.0")}");
}
public static void SolveIK(ref IKSegment segA, ref IKSegment segB, ref Transform pointA, ref Transform pointB, ref Transform pointC, Vector3 target, IKSettings settings)
{
Vector3 pA = pointA.position;
Vector3 pB = pointB.position;
Vector3 pC = pointC.position;
SolveIK(ref segA, ref segB, ref pA, ref pB, ref pC, target, settings);
pointB.position = pB;
pointC.position = pC;
var dirAC = (pC - pA).normalized;
var dirAB = (pB - pA).normalized;
var dirBC = (pC - pB).normalized;
pointA.rotation = Quaternion.LookRotation(dirAB, dirAC);
pointB.rotation = Quaternion.LookRotation(dirBC, dirAC);
}
public static void SolveIK(ref IKSegment segA, ref IKSegment segB, ref Vector3 pointA, ref Vector3 pointB, ref Vector3 pointC, Vector3 target, IKSettings settings)
{
var dir = target - pointA;
var dirXZ = new Vector3(dir.x, 0, dir.z).normalized;
var rotation = Quaternion.LookRotation(dirXZ, Vector3.up);
var matrix = Matrix4x4.TRS(pointA, rotation, Vector3.one);
var localTarget = matrix.inverse.MultiplyPoint3x4(target);
SolveIK(ref segA, ref segB, localTarget.z, localTarget.y, settings);
pointB = matrix.MultiplyPoint3x4(new Vector3(0, segA.pointB.y, segA.pointB.x));
pointC = matrix.MultiplyPoint3x4(new Vector3(0, segB.pointB.y, segB.pointB.x));
}
