internal IKArmature GetIkArmature()
{
var restArmature = GetRestArmature();
var ikArmature = new IKArmature(restArmature);
var getCorrespondingRestJoint = new Func <int, Joint>((jointIndex) =>
{
var bone = bones[jointIndex];
var restJoint = restArmature.GetJoint(bone.Name);
return(restJoint);
});
var ikJointIndexSet = new HashSet <int>();
foreach (var ikChain in ikChains)
{
var endEffectorJoint = getCorrespondingRestJoint(ikChain.EndEffectorIndex);
var endEffector = ikArmature.MakeEndEffector(endEffectorJoint.Index);
foreach (var ikBoneIndex in ikChain.AffectedBoneIndices)
{
var ikRestJoint = getCorrespondingRestJoint(ikBoneIndex);
var ikJointIndex = ikRestJoint.Index;
endEffector.AppendIkJointIndex(ikRestJoint.Index);
var joint = restArmature.GetJoint(ikRestJoint.Index);
var jointName = joint.Name;
ikJointIndexSet.Add(ikJointIndex);
}
}
foreach (var ikJointIndex in ikJointIndexSet)
{
ikArmature.MakeIkJoint(ikJointIndex);
}
return(ikArmature);
}
private void ComputeIkChainIk(Pose target_pose, Armature rest_armature, Armature morphed_armature, VpdPose vpd_pose, string ik_bone_name, IKArmature ik_armature, string root_name, string end_effector_name)
{
var root_bone = bonesByName[root_name];
var root_position = morphed_armature.GetJointWorldPosition(root_bone.Name);
var root_orientation = morphed_armature.GetJointWorldOrientation(root_bone.Name);
var end_effector_bone = bonesByName[end_effector_name];
var end_effector_position = morphed_armature.GetJointWorldPosition(end_effector_name);
var ik_bone = bonesByName[ik_bone_name];
var goal_position = GetMorphedWorldPosition(ik_bone.Index, vpd_pose);
var goal_orientation = GetMorphedWorldOrientation(ik_bone.Index, vpd_pose);
if (new[] { "leg_ik.R", "leg_ik.L", "tiptoe_ik.R", "tiptoe_ik.L" }.Contains(ik_bone_name))
{
// calculate the rotation need to rotate the vector
// (end_effector - root) to (goal - root)
var root_to_end_effector = end_effector_position - root_position;
var root_to_end_effector_length = root_to_end_effector.Length;
var root_to_goal = goal_position - root_position;
var root_to_goal_length = root_to_goal.Length;
var dot_prod = Vector3D.DotProduct(root_to_end_effector, root_to_goal);
if (root_to_end_effector_length > 0.00001)
{
dot_prod /= root_to_end_effector_length;
}
if (root_to_goal_length > 0.00001)
{
dot_prod /= root_to_goal_length;
}
if (Math.Abs(dot_prod - 1) > 0.0001)
{
var cos_theta = dot_prod;
var theta = Math.Acos(cos_theta);
var axis = Vector3D.CrossProduct(root_to_end_effector, root_to_goal);
axis.Normalize();
var rotation = new Quaternion(axis, theta * 180 / Math.PI);
root_orientation = rotation * root_orientation;
}
}
var chain_rest_armature = ik_armature.GetRestArmature();
chain_rest_armature.SetJointParameter(root_name,
(Vector3D)root_position,
root_orientation);
// create a pose with joint changes
// derived from the VPD pose.
var chain_normal_pose = new Pose();
foreach (var ik_joint in ik_armature.GetIkJoints())
{
var ik_joint_name = ik_joint.Name;
chain_normal_pose.SetJointChange(
ik_joint_name,
target_pose.GetJointChange(ik_joint_name));
}
chain_normal_pose.SetJointChange(root_name, new JointChange());
var chain_ik_pose = new IKPose();
chain_ik_pose.SetNormalPose(chain_normal_pose);
chain_ik_pose.EndEffectorGoals.SetEndEffectorPosition(end_effector_name, goal_position);
var result_pose = new Pose();
ik_armature.SolveForPose(result_pose, chain_ik_pose, 30, 0.0001);
foreach (var ik_joint in ik_armature.GetIkJoints())
{
var joint_change = result_pose.GetJointChange(ik_joint.Name);
target_pose.SetJointChange(ik_joint.Name, joint_change);
}
if (new[] { "leg_ik.R", "leg_ik.L", "tiptoe_ik.R", "tiptoe_ik.L" }.Contains(ik_bone_name))
{
// Fix the root joint change so that it is given
// with respect to its parent.
var root_parent_orientation = morphed_armature.GetJointWorldOrientation(bones[bonesByName[root_name].ParentIndex].Name);
root_parent_orientation.Invert();
var fixed_root_orientation = root_parent_orientation * root_orientation * result_pose.GetJointChange(root_name).Orientation;
target_pose.SetJointChange(root_name,
new JointChange(new Vector3D(0, 0, 0), fixed_root_orientation));
}
rest_armature.Morph(morphed_armature, target_pose);
}
private Tuple <IKArmature, string, string> GetIkChainIkArmature(int ik_chain_index)
{
var ik_chain = ikChains[ik_chain_index];
var rest_armature = new Armature();
var joint_indices = ik_chain.AffectedBoneIndices.ToList();
joint_indices.Add(ik_chain.EndEffectorIndex);
foreach (var joint_index in joint_indices)
{
rest_armature.AppendJoint(new Joint(bones[joint_index].Name));
}
string root_name = null;
foreach (var joint_index in joint_indices)
{
var bone = bones[joint_index];
if (joint_indices.Contains(bone.ParentIndex))
{
var child_name = bones[joint_index].Name;
var parent_index = bones[joint_index].ParentIndex;
var parent_name = bones[parent_index].Name;
rest_armature.SetParent(child_name, parent_name);
var joint = rest_armature.GetJoint(child_name);
var m = Matrix3D.Identity;
m.Scale(new Vector3D(1, 1, -1));
var position = m.Transform(bones[joint_index].Position - bones[parent_index].Position);
joint.Position = position;
}
else
{
root_name = bone.Name;
}
}
var ik_bone_name = bones[ik_chain.IkBoneIndex].Name;
var ik_armature = new IKArmature(rest_armature);
var end_effector_name = bones[ik_chain.EndEffectorIndex].Name;
ik_armature.MakeEndEffector(end_effector_name);
foreach (var joint_index in ik_chain.AffectedBoneIndices)
{
var bone = bones[joint_index];
var ik_joint = ik_armature.MakeIkJoint(bone.Name);
ik_armature.AddIkJointToEndEffector(bone.Name, end_effector_name);
ik_joint.DisableParameter(IKJointParameters.XTranslate);
ik_joint.DisableParameter(IKJointParameters.YTranslate);
ik_joint.DisableParameter(IKJointParameters.ZTranslate);
}
if (new[] { "leg_ik.R", "leg_ik.L" }.Contains(ik_bone_name))
{
IKJoint knee_joint;
IKJoint leg_joint;
if (ik_bone_name == "leg_ik.R")
{
knee_joint = ik_armature.GetIkJoint("knee.R");
leg_joint = ik_armature.GetIkJoint("leg.R");
}
else
{
leg_joint = ik_armature.GetIkJoint("leg.L");
knee_joint = ik_armature.GetIkJoint("knee.L");
}
knee_joint.DisableParameter(IKJointParameters.YRotate);
knee_joint.DisableParameter(IKJointParameters.ZRotate);
knee_joint.SetLimit(IKJointParameters.XRotate, 0, 180);
leg_joint.DisableParameter(IKJointParameters.YRotate);
leg_joint.DisableParameter(IKJointParameters.ZRotate);
}
return(Tuple.Create(ik_armature, root_name, end_effector_name));
}
