overte-HifiExperiments/libraries/animation/src/AnimInverseKinematics.cpp
2015-10-02 11:40:33 -07:00

716 lines
32 KiB
C++

//
// AnimInverseKinematics.cpp
//
// Copyright 2015 High Fidelity, Inc.
//
// Distributed under the Apache License, Version 2.0.
// See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//
#include "AnimInverseKinematics.h"
#include <GeometryUtil.h>
#include <GLMHelpers.h>
#include <NumericalConstants.h>
#include <SharedUtil.h>
#include "ElbowConstraint.h"
#include "SwingTwistConstraint.h"
#include "AnimationLogging.h"
AnimInverseKinematics::AnimInverseKinematics(const QString& id) : AnimNode(AnimNode::Type::InverseKinematics, id) {
}
AnimInverseKinematics::~AnimInverseKinematics() {
clearConstraints();
}
void AnimInverseKinematics::loadDefaultPoses(const AnimPoseVec& poses) {
_defaultRelativePoses = poses;
assert(_skeleton && _skeleton->getNumJoints() == (int)poses.size());
}
void AnimInverseKinematics::loadPoses(const AnimPoseVec& poses) {
assert(_skeleton && ((poses.size() == 0) || (_skeleton->getNumJoints() == (int)poses.size())));
if (_skeleton->getNumJoints() == (int)poses.size()) {
_relativePoses = poses;
_accumulators.resize(_relativePoses.size());
} else {
_relativePoses.clear();
_accumulators.clear();
}
}
void AnimInverseKinematics::computeAbsolutePoses(AnimPoseVec& absolutePoses) const {
int numJoints = (int)_relativePoses.size();
assert(numJoints <= _skeleton->getNumJoints());
assert(numJoints == (int)absolutePoses.size());
for (int i = 0; i < numJoints; ++i) {
int parentIndex = _skeleton->getParentIndex(i);
if (parentIndex < 0) {
absolutePoses[i] = _relativePoses[i];
} else {
absolutePoses[i] = absolutePoses[parentIndex] * _relativePoses[i];
}
}
}
void AnimInverseKinematics::setTargetVars(
const QString& jointName,
const QString& positionVar,
const QString& rotationVar,
const QString& typeVar) {
// if there are dups, last one wins.
bool found = false;
for (auto& targetVar: _targetVarVec) {
if (targetVar.jointName == jointName) {
// update existing targetVar
targetVar.positionVar = positionVar;
targetVar.rotationVar = rotationVar;
targetVar.typeVar = typeVar;
found = true;
break;
}
}
if (!found) {
// create a new entry
_targetVarVec.push_back(IKTargetVar(jointName, positionVar, rotationVar, typeVar));
}
}
static int findRootJointInSkeleton(AnimSkeleton::ConstPointer skeleton, int index) {
// walk down the skeleton hierarchy to find the joint's root
int rootIndex = -1;
int parentIndex = skeleton->getParentIndex(index);
while (parentIndex != -1) {
rootIndex = parentIndex;
parentIndex = skeleton->getParentIndex(parentIndex);
}
return rootIndex;
}
void AnimInverseKinematics::computeTargets(const AnimVariantMap& animVars, std::vector<IKTarget>& targets, const AnimPoseVec& underPoses) {
// build a list of valid targets from _targetVarVec and animVars
_maxTargetIndex = -1;
bool removeUnfoundJoints = false;
for (auto& targetVar : _targetVarVec) {
if (targetVar.jointIndex == -1) {
// this targetVar hasn't been validated yet...
int jointIndex = _skeleton->nameToJointIndex(targetVar.jointName);
if (jointIndex >= 0) {
// this targetVar has a valid joint --> cache the indices
targetVar.jointIndex = jointIndex;
targetVar.rootIndex = findRootJointInSkeleton(_skeleton, jointIndex);
} else {
qCWarning(animation) << "AnimInverseKinematics could not find jointName" << targetVar.jointName << "in skeleton";
removeUnfoundJoints = true;
}
} else {
IKTarget target;
AnimPose defaultPose = _skeleton->getAbsolutePose(targetVar.jointIndex, underPoses);
target.pose.trans = animVars.lookup(targetVar.positionVar, defaultPose.trans);
target.pose.rot = animVars.lookup(targetVar.rotationVar, defaultPose.rot);
target.setType(animVars.lookup(targetVar.typeVar, QString("")));
target.rootIndex = targetVar.rootIndex;
target.index = targetVar.jointIndex;
targets.push_back(target);
if (target.index > _maxTargetIndex) {
_maxTargetIndex = target.index;
}
}
}
if (removeUnfoundJoints) {
int numVars = _targetVarVec.size();
int i = 0;
while (i < numVars) {
if (_targetVarVec[i].jointIndex == -1) {
if (numVars > 1) {
// swap i for last element
_targetVarVec[i] = _targetVarVec[numVars - 1];
}
_targetVarVec.pop_back();
--numVars;
} else {
++i;
}
}
}
}
void AnimInverseKinematics::solveWithCyclicCoordinateDescent(const std::vector<IKTarget>& targets) {
// compute absolute poses that correspond to relative target poses
AnimPoseVec absolutePoses;
absolutePoses.resize(_relativePoses.size());
computeAbsolutePoses(absolutePoses);
// clear the accumulators before we start the IK solver
for (auto& accumulator: _accumulators) {
accumulator.clearAndClean();
}
int numLoops = 0;
const int MAX_IK_LOOPS = 4;
do {
int lowestMovedIndex = _relativePoses.size();
for (auto& target: targets) {
if (target.type == IKTarget::Type::RotationOnly) {
// the final rotation will be enforced after the iterations
continue;
}
AnimPose targetPose = target.pose;
// cache tip absolute transform
int tipIndex = target.index;
glm::vec3 tipPosition = absolutePoses[tipIndex].trans;
glm::quat tipRotation = absolutePoses[tipIndex].rot;
// cache tip's parent's absolute rotation so we can recompute the tip's parent-relative
// as we proceed walking down the joint chain
int pivotIndex = _skeleton->getParentIndex(tipIndex);
glm::quat tipParentRotation;
if (pivotIndex != -1) {
tipParentRotation = absolutePoses[pivotIndex].rot;
}
// descend toward root, pivoting each joint to get tip closer to target
int ancestorCount = 1;
while (pivotIndex != -1) {
// compute the two lines that should be aligned
glm::vec3 jointPosition = absolutePoses[pivotIndex].trans;
glm::vec3 leverArm = tipPosition - jointPosition;
glm::vec3 targetLine = targetPose.trans - jointPosition;
// compute the swing that would get get tip closer
glm::vec3 axis = glm::cross(leverArm, targetLine);
float axisLength = glm::length(axis);
glm::quat deltaRotation;
const float MIN_AXIS_LENGTH = 1.0e-4f;
if (axisLength > MIN_AXIS_LENGTH) {
// compute deltaRotation for alignment (swings tip closer to target)
axis /= axisLength;
float angle = acosf(glm::dot(leverArm, targetLine) / (glm::length(leverArm) * glm::length(targetLine)));
// NOTE: even when axisLength is not zero (e.g. lever-arm and pivot-arm are not quite aligned) it is
// still possible for the angle to be zero so we also check that to avoid unnecessary calculations.
const float MIN_ADJUSTMENT_ANGLE = 1.0e-4f;
if (angle > MIN_ADJUSTMENT_ANGLE) {
// reduce angle by a fraction (reduces IK swing contribution of this joint)
angle /= (float)ancestorCount;
deltaRotation = glm::angleAxis(angle, axis);
}
// The swing will re-orient the tip but there will tend to be be a non-zero delta between the tip's
// new rotation and its target. We compute that delta here and rotate the tipJoint accordingly.
glm::quat tipRelativeRotation = glm::inverse(deltaRotation * tipParentRotation) * targetPose.rot;
// enforce tip's constraint
RotationConstraint* constraint = getConstraint(tipIndex);
if (constraint) {
bool constrained = constraint->apply(tipRelativeRotation);
if (constrained) {
// The tip's final parent-relative rotation violates its constraint
// so we try to twist this pivot to compensate.
glm::quat constrainedTipRotation = deltaRotation * tipParentRotation * tipRelativeRotation;
glm::quat missingRotation = targetPose.rot * glm::inverse(constrainedTipRotation);
glm::quat swingPart;
glm::quat twistPart;
glm::vec3 axis = glm::normalize(deltaRotation * leverArm);
swingTwistDecomposition(missingRotation, axis, swingPart, twistPart);
deltaRotation = twistPart * deltaRotation;
}
// we update the tip rotation here to rotate it as close to its target orientation as possible
// before moving on to next pivot
tipRotation = tipParentRotation * tipRelativeRotation;
}
}
++ancestorCount;
int parentIndex = _skeleton->getParentIndex(pivotIndex);
if (parentIndex == -1) {
// TODO? apply constraints to root?
// TODO? harvest the root's transform as movement of entire skeleton?
} else {
// compute joint's new parent-relative rotation after swing
// Q' = dQ * Q and Q = Qp * q --> q' = Qp^ * dQ * Q
glm::quat newRot = glm::normalize(glm::inverse(
absolutePoses[parentIndex].rot) *
deltaRotation *
absolutePoses[pivotIndex].rot);
// enforce pivot's constraint
RotationConstraint* constraint = getConstraint(pivotIndex);
if (constraint) {
bool constrained = constraint->apply(newRot);
if (constrained) {
// the constraint will modify the movement of the tip so we have to compute the modified
// model-frame deltaRotation
// Q' = Qp^ * dQ * Q --> dQ = Qp * Q' * Q^
deltaRotation = absolutePoses[parentIndex].rot *
newRot *
glm::inverse(absolutePoses[pivotIndex].rot);
}
}
// store the rotation change in the accumulator
_accumulators[pivotIndex].add(newRot);
}
// this joint has been changed so we check to see if it has the lowest index
if (pivotIndex < lowestMovedIndex) {
lowestMovedIndex = pivotIndex;
}
// keep track of tip's new transform as we descend towards root
tipPosition = jointPosition + deltaRotation * leverArm;
tipRotation = glm::normalize(deltaRotation * tipRotation);
tipParentRotation = glm::normalize(deltaRotation * tipParentRotation);
pivotIndex = _skeleton->getParentIndex(pivotIndex);
}
}
++numLoops;
// harvest accumulated rotations and apply the average
const int numJoints = (int)_accumulators.size();
for (int i = 0; i < numJoints; ++i) {
if (_accumulators[i].size() > 0) {
_relativePoses[i].rot = _accumulators[i].getAverage();
_accumulators[i].clear();
}
}
// only update the absolutePoses that need it: those between lowestMovedIndex and _maxTargetIndex
for (int i = lowestMovedIndex; i <= _maxTargetIndex; ++i) {
int parentIndex = _skeleton->getParentIndex(i);
if (parentIndex != -1) {
absolutePoses[i] = absolutePoses[parentIndex] * _relativePoses[i];
}
}
} while (numLoops < MAX_IK_LOOPS);
/* KEEP: example code for measuring endeffector error of IK solution
for (uint32_t i = 0; i < targets.size(); ++i) {
auto& target = targets[i];
if (target.type == IKTarget::Type::RotationOnly) {
continue;
}
glm::vec3 tipPosition = absolutePoses[target.index].trans;
std::cout << i << " IK error = " << glm::distance(tipPosition, target.pose.trans) << std::endl; // adebug
}
*/
// finally set the relative rotation of each tip to agree with absolute target rotation
for (auto& target: targets) {
int tipIndex = target.index;
int parentIndex = _skeleton->getParentIndex(tipIndex);
if (parentIndex != -1) {
AnimPose targetPose = target.pose;
// compute tip's new parent-relative rotation
// Q = Qp * q --> q' = Qp^ * Q
glm::quat newRelativeRotation = glm::inverse(absolutePoses[parentIndex].rot) * targetPose.rot;
RotationConstraint* constraint = getConstraint(tipIndex);
if (constraint) {
constraint->apply(newRelativeRotation);
// TODO: ATM the final rotation target just fails but we need to provide
// feedback to the IK system so that it can adjust the bones up the skeleton
// to help this rotation target get met.
}
_relativePoses[tipIndex].rot = newRelativeRotation;
absolutePoses[tipIndex].rot = targetPose.rot;
}
}
}
//virtual
const AnimPoseVec& AnimInverseKinematics::evaluate(const AnimVariantMap& animVars, float dt, AnimNode::Triggers& triggersOut) {
// don't call this function, call overlay() instead
assert(false);
return _relativePoses;
}
//virtual
const AnimPoseVec& AnimInverseKinematics::overlay(const AnimVariantMap& animVars, float dt, Triggers& triggersOut, const AnimPoseVec& underPoses) {
if (_relativePoses.size() != underPoses.size()) {
loadPoses(underPoses);
} else {
// relax toward underpose
// HACK: this relaxation needs to be constant per-frame rather than per-realtime
// in order to prevent IK "flutter" for bad FPS. The bad news is that the good parts
// of this relaxation will be FPS dependent (low FPS will make the limbs align slower
// in real-time), however most people will not notice this and this problem is less
// annoying than the flutter.
const float blend = (1.0f / 60.0f) / (0.25f); // effectively: dt / RELAXATION_TIMESCALE
int numJoints = (int)_relativePoses.size();
for (int i = 0; i < numJoints; ++i) {
float dotSign = copysignf(1.0f, glm::dot(_relativePoses[i].rot, underPoses[i].rot));
if (_accumulators[i].isDirty()) {
_relativePoses[i].rot = glm::normalize(glm::lerp(_relativePoses[i].rot, dotSign * underPoses[i].rot, blend));
} else {
_relativePoses[i].rot = underPoses[i].rot;
}
_relativePoses[i].trans = underPoses[i].trans;
}
}
if (!_relativePoses.empty()) {
// build a list of targets from _targetVarVec
std::vector<IKTarget> targets;
computeTargets(animVars, targets, underPoses);
if (targets.empty()) {
// no IK targets but still need to enforce constraints
std::map<int, RotationConstraint*>::iterator constraintItr = _constraints.begin();
while (constraintItr != _constraints.end()) {
int index = constraintItr->first;
glm::quat rotation = _relativePoses[index].rot;
constraintItr->second->apply(rotation);
_relativePoses[index].rot = rotation;
++constraintItr;
}
} else {
solveWithCyclicCoordinateDescent(targets);
}
}
return _relativePoses;
}
RotationConstraint* AnimInverseKinematics::getConstraint(int index) {
RotationConstraint* constraint = nullptr;
std::map<int, RotationConstraint*>::iterator constraintItr = _constraints.find(index);
if (constraintItr != _constraints.end()) {
constraint = constraintItr->second;
}
return constraint;
}
void AnimInverseKinematics::clearConstraints() {
std::map<int, RotationConstraint*>::iterator constraintItr = _constraints.begin();
while (constraintItr != _constraints.end()) {
delete constraintItr->second;
++constraintItr;
}
_constraints.clear();
}
void AnimInverseKinematics::initConstraints() {
if (!_skeleton) {
return;
}
// We create constraints for the joints shown here
// (and their Left counterparts if applicable).
//
//
// O RightHand
// Head /
// O /
// Neck| O RightForeArm
// O /
// O | O / RightShoulder
// O-------O-------O' \|/ 'O
// Spine2 O RightArm
// |
// |
// Spine1 O
// |
// |
// Spine O
// y |
// | |
// | O---O---O RightUpLeg
// z | | Hips2 |
// \ | | |
// \| | |
// x -----+ O O RightLeg
// | |
// | |
// | |
// O O RightFoot
// / /
// O--O O--O
loadDefaultPoses(_skeleton->getRelativeBindPoses());
// compute corresponding absolute poses
int numJoints = (int)_defaultRelativePoses.size();
AnimPoseVec absolutePoses;
absolutePoses.resize(numJoints);
for (int i = 0; i < numJoints; ++i) {
int parentIndex = _skeleton->getParentIndex(i);
if (parentIndex < 0) {
absolutePoses[i] = _defaultRelativePoses[i];
} else {
absolutePoses[i] = absolutePoses[parentIndex] * _defaultRelativePoses[i];
}
}
clearConstraints();
for (int i = 0; i < numJoints; ++i) {
// compute the joint's baseName and remember whether its prefix was "Left" or not
QString baseName = _skeleton->getJointName(i);
bool isLeft = baseName.startsWith("Left", Qt::CaseInsensitive);
float mirror = isLeft ? -1.0f : 1.0f;
if (isLeft) {
baseName.remove(0, 4);
} else if (baseName.startsWith("Right", Qt::CaseInsensitive)) {
baseName.remove(0, 5);
}
RotationConstraint* constraint = nullptr;
if (0 == baseName.compare("Arm", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
stConstraint->setTwistLimits(-PI / 2.0f, PI / 2.0f);
/* KEEP THIS CODE for future experimentation
// these directions are approximate swing limits in root-frame
// NOTE: they don't need to be normalized
std::vector<glm::vec3> swungDirections;
swungDirections.push_back(glm::vec3(mirror * 1.0f, 1.0f, 1.0f));
swungDirections.push_back(glm::vec3(mirror * 1.0f, 0.0f, 1.0f));
swungDirections.push_back(glm::vec3(mirror * 1.0f, -1.0f, 0.5f));
swungDirections.push_back(glm::vec3(mirror * 0.0f, -1.0f, 0.0f));
swungDirections.push_back(glm::vec3(mirror * 0.0f, -1.0f, -1.0f));
swungDirections.push_back(glm::vec3(mirror * -0.5f, 0.0f, -1.0f));
swungDirections.push_back(glm::vec3(mirror * 0.0f, 1.0f, -1.0f));
swungDirections.push_back(glm::vec3(mirror * 0.0f, 1.0f, 0.0f));
// rotate directions into joint-frame
glm::quat invAbsoluteRotation = glm::inverse(absolutePoses[i].rot);
int numDirections = (int)swungDirections.size();
for (int j = 0; j < numDirections; ++j) {
swungDirections[j] = invAbsoluteRotation * swungDirections[j];
}
stConstraint->setSwingLimits(swungDirections);
*/
// simple cone
std::vector<float> minDots;
const float MAX_HAND_SWING = PI / 2.0f;
minDots.push_back(cosf(MAX_HAND_SWING));
stConstraint->setSwingLimits(minDots);
constraint = static_cast<RotationConstraint*>(stConstraint);
} else if (0 == baseName.compare("UpLegXXX", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
stConstraint->setTwistLimits(-PI / 4.0f, PI / 4.0f);
// these directions are approximate swing limits in root-frame
// NOTE: they don't need to be normalized
std::vector<glm::vec3> swungDirections;
swungDirections.push_back(glm::vec3(mirror * 0.25f, 0.0f, 1.0f));
swungDirections.push_back(glm::vec3(mirror * -0.5f, 0.0f, 1.0f));
swungDirections.push_back(glm::vec3(mirror * -1.0f, 0.0f, 1.0f));
swungDirections.push_back(glm::vec3(mirror * -1.0f, 0.0f, 0.0f));
swungDirections.push_back(glm::vec3(mirror * -0.5f, -0.5f, -1.0f));
swungDirections.push_back(glm::vec3(mirror * 0.0f, -0.75f, -1.0f));
swungDirections.push_back(glm::vec3(mirror * 0.25f, -1.0f, 0.0f));
swungDirections.push_back(glm::vec3(mirror * 0.25f, -1.0f, 1.0f));
// rotate directions into joint-frame
glm::quat invAbsoluteRotation = glm::inverse(absolutePoses[i].rot);
int numDirections = (int)swungDirections.size();
for (int j = 0; j < numDirections; ++j) {
swungDirections[j] = invAbsoluteRotation * swungDirections[j];
}
stConstraint->setSwingLimits(swungDirections);
constraint = static_cast<RotationConstraint*>(stConstraint);
} else if (0 == baseName.compare("Hand", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
const float MAX_HAND_TWIST = 3.0f * PI / 5.0f;
const float MIN_HAND_TWIST = -PI / 2.0f;
if (isLeft) {
stConstraint->setTwistLimits(-MAX_HAND_TWIST, -MIN_HAND_TWIST);
} else {
stConstraint->setTwistLimits(MIN_HAND_TWIST, MAX_HAND_TWIST);
}
/* KEEP THIS CODE for future experimentation
* a more complicated wrist with asymmetric cone
// these directions are approximate swing limits in parent-frame
// NOTE: they don't need to be normalized
std::vector<glm::vec3> swungDirections;
swungDirections.push_back(glm::vec3(1.0f, 1.0f, 0.0f));
swungDirections.push_back(glm::vec3(0.75f, 1.0f, -1.0f));
swungDirections.push_back(glm::vec3(-0.75f, 1.0f, -1.0f));
swungDirections.push_back(glm::vec3(-1.0f, 1.0f, 0.0f));
swungDirections.push_back(glm::vec3(-0.75f, 1.0f, 1.0f));
swungDirections.push_back(glm::vec3(0.75f, 1.0f, 1.0f));
// rotate directions into joint-frame
glm::quat invRelativeRotation = glm::inverse(_defaultRelativePoses[i].rot);
int numDirections = (int)swungDirections.size();
for (int j = 0; j < numDirections; ++j) {
swungDirections[j] = invRelativeRotation * swungDirections[j];
}
stConstraint->setSwingLimits(swungDirections);
*/
// simple cone
std::vector<float> minDots;
const float MAX_HAND_SWING = PI / 2.0f;
minDots.push_back(cosf(MAX_HAND_SWING));
stConstraint->setSwingLimits(minDots);
constraint = static_cast<RotationConstraint*>(stConstraint);
} else if (baseName.startsWith("Shoulder", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
const float MAX_SHOULDER_TWIST = PI / 20.0f;
stConstraint->setTwistLimits(-MAX_SHOULDER_TWIST, MAX_SHOULDER_TWIST);
std::vector<float> minDots;
const float MAX_SHOULDER_SWING = PI / 20.0f;
minDots.push_back(cosf(MAX_SHOULDER_SWING));
stConstraint->setSwingLimits(minDots);
constraint = static_cast<RotationConstraint*>(stConstraint);
} else if (baseName.startsWith("Spine", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
const float MAX_SPINE_TWIST = PI / 8.0f;
stConstraint->setTwistLimits(-MAX_SPINE_TWIST, MAX_SPINE_TWIST);
std::vector<float> minDots;
const float MAX_SPINE_SWING = PI / 14.0f;
minDots.push_back(cosf(MAX_SPINE_SWING));
stConstraint->setSwingLimits(minDots);
constraint = static_cast<RotationConstraint*>(stConstraint);
} else if (baseName.startsWith("Hips2", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
const float MAX_SPINE_TWIST = PI / 8.0f;
stConstraint->setTwistLimits(-MAX_SPINE_TWIST, MAX_SPINE_TWIST);
std::vector<float> minDots;
const float MAX_SPINE_SWING = PI / 14.0f;
minDots.push_back(cosf(MAX_SPINE_SWING));
stConstraint->setSwingLimits(minDots);
constraint = static_cast<RotationConstraint*>(stConstraint);
} else if (0 == baseName.compare("Neck", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
const float MAX_NECK_TWIST = PI / 2.0f;
stConstraint->setTwistLimits(-MAX_NECK_TWIST, MAX_NECK_TWIST);
std::vector<float> minDots;
const float MAX_NECK_SWING = PI / 3.0f;
minDots.push_back(cosf(MAX_NECK_SWING));
stConstraint->setSwingLimits(minDots);
constraint = static_cast<RotationConstraint*>(stConstraint);
} else if (0 == baseName.compare("ForeArm", Qt::CaseInsensitive)) {
// The elbow joint rotates about the parent-frame's zAxis (-zAxis) for the Right (Left) arm.
ElbowConstraint* eConstraint = new ElbowConstraint();
glm::quat referenceRotation = _defaultRelativePoses[i].rot;
eConstraint->setReferenceRotation(referenceRotation);
// we determine the max/min angles by rotating the swing limit lines from parent- to child-frame
// then measure the angles to swing the yAxis into alignment
glm::vec3 hingeAxis = - mirror * Vectors::UNIT_Z;
const float MIN_ELBOW_ANGLE = 0.05f;
const float MAX_ELBOW_ANGLE = 11.0f * PI / 12.0f;
glm::quat invReferenceRotation = glm::inverse(referenceRotation);
glm::vec3 minSwingAxis = invReferenceRotation * glm::angleAxis(MIN_ELBOW_ANGLE, hingeAxis) * Vectors::UNIT_Y;
glm::vec3 maxSwingAxis = invReferenceRotation * glm::angleAxis(MAX_ELBOW_ANGLE, hingeAxis) * Vectors::UNIT_Y;
// for the rest of the math we rotate hingeAxis into the child frame
hingeAxis = referenceRotation * hingeAxis;
eConstraint->setHingeAxis(hingeAxis);
glm::vec3 projectedYAxis = glm::normalize(Vectors::UNIT_Y - glm::dot(Vectors::UNIT_Y, hingeAxis) * hingeAxis);
float minAngle = acosf(glm::dot(projectedYAxis, minSwingAxis));
if (glm::dot(hingeAxis, glm::cross(projectedYAxis, minSwingAxis)) < 0.0f) {
minAngle = - minAngle;
}
float maxAngle = acosf(glm::dot(projectedYAxis, maxSwingAxis));
if (glm::dot(hingeAxis, glm::cross(projectedYAxis, maxSwingAxis)) < 0.0f) {
maxAngle = - maxAngle;
}
eConstraint->setAngleLimits(minAngle, maxAngle);
constraint = static_cast<RotationConstraint*>(eConstraint);
} else if (0 == baseName.compare("LegXXX", Qt::CaseInsensitive)) {
// The knee joint rotates about the parent-frame's -xAxis.
ElbowConstraint* eConstraint = new ElbowConstraint();
glm::quat referenceRotation = _defaultRelativePoses[i].rot;
eConstraint->setReferenceRotation(referenceRotation);
glm::vec3 hingeAxis = -1.0f * Vectors::UNIT_X;
// we determine the max/min angles by rotating the swing limit lines from parent- to child-frame
// then measure the angles to swing the yAxis into alignment
const float MIN_KNEE_ANGLE = 0.0f;
const float MAX_KNEE_ANGLE = 3.0f * PI / 4.0f;
glm::quat invReferenceRotation = glm::inverse(referenceRotation);
glm::vec3 minSwingAxis = invReferenceRotation * glm::angleAxis(MIN_KNEE_ANGLE, hingeAxis) * Vectors::UNIT_Y;
glm::vec3 maxSwingAxis = invReferenceRotation * glm::angleAxis(MAX_KNEE_ANGLE, hingeAxis) * Vectors::UNIT_Y;
// for the rest of the math we rotate hingeAxis into the child frame
hingeAxis = referenceRotation * hingeAxis;
eConstraint->setHingeAxis(hingeAxis);
glm::vec3 projectedYAxis = glm::normalize(Vectors::UNIT_Y - glm::dot(Vectors::UNIT_Y, hingeAxis) * hingeAxis);
float minAngle = acosf(glm::dot(projectedYAxis, minSwingAxis));
if (glm::dot(hingeAxis, glm::cross(projectedYAxis, minSwingAxis)) < 0.0f) {
minAngle = - minAngle;
}
float maxAngle = acosf(glm::dot(projectedYAxis, maxSwingAxis));
if (glm::dot(hingeAxis, glm::cross(projectedYAxis, maxSwingAxis)) < 0.0f) {
maxAngle = - maxAngle;
}
eConstraint->setAngleLimits(minAngle, maxAngle);
constraint = static_cast<RotationConstraint*>(eConstraint);
} else if (0 == baseName.compare("FootXXX", Qt::CaseInsensitive)) {
SwingTwistConstraint* stConstraint = new SwingTwistConstraint();
stConstraint->setReferenceRotation(_defaultRelativePoses[i].rot);
stConstraint->setTwistLimits(-PI / 4.0f, PI / 4.0f);
// these directions are approximate swing limits in parent-frame
// NOTE: they don't need to be normalized
std::vector<glm::vec3> swungDirections;
swungDirections.push_back(Vectors::UNIT_Y);
swungDirections.push_back(Vectors::UNIT_X);
swungDirections.push_back(glm::vec3(1.0f, 1.0f, 1.0f));
swungDirections.push_back(glm::vec3(1.0f, 1.0f, -1.0f));
// rotate directions into joint-frame
glm::quat invRelativeRotation = glm::inverse(_defaultRelativePoses[i].rot);
int numDirections = (int)swungDirections.size();
for (int j = 0; j < numDirections; ++j) {
swungDirections[j] = invRelativeRotation * swungDirections[j];
}
stConstraint->setSwingLimits(swungDirections);
constraint = static_cast<RotationConstraint*>(stConstraint);
}
if (constraint) {
_constraints[i] = constraint;
}
}
}
void AnimInverseKinematics::setSkeletonInternal(AnimSkeleton::ConstPointer skeleton) {
AnimNode::setSkeletonInternal(skeleton);
// invalidate all targetVars
for (auto& targetVar: _targetVarVec) {
targetVar.jointIndex = -1;
}
_maxTargetIndex = -1;
for (auto& accumulator: _accumulators) {
accumulator.clearAndClean();
}
if (skeleton) {
initConstraints();
} else {
clearConstraints();
}
}