/// <summary>
/// Perform an iteration of IK
/// </summary>
private void UpdateIK()
{
int numBones = Bones.Count;
if (numBones == 0)
{
return;
}
// calculate the bone angles
List <Bone_2D_ConstraintRelaxation> relaxBones = new List <Bone_2D_ConstraintRelaxation> ();
for (int boneIdx = 0; boneIdx < numBones; ++boneIdx)
{
Bone_2D_ConstraintRelaxation newRelaxBone = new Bone_2D_ConstraintRelaxation();
newRelaxBone.angle = Bones [boneIdx].Radians;
newRelaxBone.length = Bones [boneIdx].Length;
newRelaxBone.weight = Bones [boneIdx].Weight;
relaxBones.Add(newRelaxBone);
}
// convert to worldspace bones
List <Bone_2D_ConstraintRelaxation_World> worldBones;
CalcIK_2D_ConstraintRelaxation_ConvertToWorld(out worldBones, relaxBones);
// iterate IK
for (int itrCount = 0; itrCount < IterationsPerUpdate; ++itrCount)
{
CalcIK_2D_ConstraintRelaxation(ref worldBones, TargetPosX, TargetPosY);
}
// convert bones back to local space
CalcIK_2D_ConstraintRelaxation_ConvertToLocal(ref relaxBones, worldBones, TargetPosX, TargetPosY);
// extract the new bone data from the results
for (int boneIdx = 0; boneIdx < numBones; ++boneIdx)
{
Bones [boneIdx].Radians = relaxBones [boneIdx].angle;
Bones [boneIdx].RelaxedX = worldBones [boneIdx].x;
Bones [boneIdx].RelaxedY = worldBones [boneIdx].y;
}
// track the target position we used for relaxation (this prevents the relaxed bone display from changing while paused)
m_relaxedTargetX = TargetPosX;
m_relaxedTargetY = TargetPosY;
}
///***************************************************************************************
/// CalcIK_2D_ConstraintRelaxation_ConvertToWorld
/// This is a helper function to generate a world space bone chain for relaxation given
/// a local space bone chain.
///***************************************************************************************
public static void CalcIK_2D_ConstraintRelaxation_ConvertToWorld
(
out List <Bone_2D_ConstraintRelaxation_World> worldBones, // Output world space bones
List <Bone_2D_ConstraintRelaxation> localBones // Input local space bones
)
{
int numBones = localBones.Count;
//Debug.Assert (numBones > 0);
// create the list to output
worldBones = new List <Bone_2D_ConstraintRelaxation_World> ();
// Start with the root bone.
Bone_2D_ConstraintRelaxation_World rootWorldBone
= new Bone_2D_ConstraintRelaxation_World();
rootWorldBone.x = 0;
rootWorldBone.y = 0;
rootWorldBone.length = localBones [0].length;
rootWorldBone.weight = localBones [0].weight;
worldBones.Add(rootWorldBone);
double prevAngle = localBones [0].angle;
double prevAngleCos = Math.Cos(prevAngle);
double prevAngleSin = Math.Sin(prevAngle);
// Convert child bones to world space.
for (int boneIdx = 1; boneIdx < numBones; ++boneIdx)
{
Bone_2D_ConstraintRelaxation_World prevWorldBone = worldBones [boneIdx - 1];
Bone_2D_ConstraintRelaxation prevLocalBone = localBones [boneIdx - 1];
Bone_2D_ConstraintRelaxation_World newWorldBone
= new Bone_2D_ConstraintRelaxation_World();
newWorldBone.x = prevWorldBone.x + prevAngleCos * prevLocalBone.length;
newWorldBone.y = prevWorldBone.y + prevAngleSin * prevLocalBone.length;
newWorldBone.length = localBones [boneIdx].length;
newWorldBone.weight = localBones [boneIdx].weight;
worldBones.Add(newWorldBone);
prevAngle = prevAngle + localBones [boneIdx].angle;
prevAngleCos = Math.Cos(prevAngle);
prevAngleSin = Math.Sin(prevAngle);
}
}
/// <summary>
/// Perform an iteration of IK
/// </summary>
private void UpdateIK()
{
int numBones = Bones.Count;
if (numBones == 0)
return;
// calculate the bone angles
List< Bone_2D_ConstraintRelaxation > relaxBones = new List< Bone_2D_ConstraintRelaxation > ();
for (int boneIdx = 0; boneIdx < numBones; ++boneIdx) {
Bone_2D_ConstraintRelaxation newRelaxBone = new Bone_2D_ConstraintRelaxation ();
newRelaxBone.angle = Bones [boneIdx].Radians;
newRelaxBone.length = Bones [boneIdx].Length;
newRelaxBone.weight = Bones [boneIdx].Weight;
relaxBones.Add (newRelaxBone);
}
// convert to worldspace bones
List< Bone_2D_ConstraintRelaxation_World > worldBones;
CalcIK_2D_ConstraintRelaxation_ConvertToWorld (out worldBones, relaxBones);
// iterate IK
for (int itrCount = 0; itrCount < IterationsPerUpdate; ++itrCount) {
CalcIK_2D_ConstraintRelaxation (ref worldBones, TargetPosX, TargetPosY);
}
// convert bones back to local space
CalcIK_2D_ConstraintRelaxation_ConvertToLocal (ref relaxBones, worldBones, TargetPosX, TargetPosY);
// extract the new bone data from the results
for (int boneIdx = 0; boneIdx < numBones; ++boneIdx) {
Bones [boneIdx].Radians = relaxBones [boneIdx].angle;
Bones [boneIdx].RelaxedX = worldBones [boneIdx].x;
Bones [boneIdx].RelaxedY = worldBones [boneIdx].y;
}
// track the target position we used for relaxation (this prevents the relaxed bone display from changing while paused)
m_relaxedTargetX = TargetPosX;
m_relaxedTargetY = TargetPosY;
}