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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*/
/** \file
* \ingroup iksolver
*/
#include <stdio.h>
#include "IK_QJacobianSolver.h"
//#include "analyze.h"
IK_QJacobianSolver::IK_QJacobianSolver()
{
m_poleconstraint = false;
m_getpoleangle = false;
m_rootmatrix.setIdentity();
}
double IK_QJacobianSolver::ComputeScale()
{
std::vector<IK_QSegment *>::iterator seg;
double length = 0.0f;
for (seg = m_segments.begin(); seg != m_segments.end(); seg++)
length += (*seg)->MaxExtension();
if (length == 0.0)
return 1.0;
else
return 1.0 / length;
}
void IK_QJacobianSolver::Scale(double scale, std::list<IK_QTask *> &tasks)
{
std::list<IK_QTask *>::iterator task;
std::vector<IK_QSegment *>::iterator seg;
for (task = tasks.begin(); task != tasks.end(); task++)
(*task)->Scale(scale);
for (seg = m_segments.begin(); seg != m_segments.end(); seg++)
(*seg)->Scale(scale);
m_rootmatrix.translation() *= scale;
m_goal *= scale;
m_polegoal *= scale;
}
void IK_QJacobianSolver::AddSegmentList(IK_QSegment *seg)
{
m_segments.push_back(seg);
IK_QSegment *child;
for (child = seg->Child(); child; child = child->Sibling())
AddSegmentList(child);
}
bool IK_QJacobianSolver::Setup(IK_QSegment *root, std::list<IK_QTask *> &tasks)
{
m_segments.clear();
AddSegmentList(root);
// assign each segment a unique id for the jacobian
std::vector<IK_QSegment *>::iterator seg;
int num_dof = 0;
for (seg = m_segments.begin(); seg != m_segments.end(); seg++) {
(*seg)->SetDoFId(num_dof);
num_dof += (*seg)->NumberOfDoF();
}
if (num_dof == 0)
return false;
// compute task ids and assign weights to task
int primary_size = 0, primary = 0;
int secondary_size = 0, secondary = 0;
double primary_weight = 0.0, secondary_weight = 0.0;
std::list<IK_QTask *>::iterator task;
for (task = tasks.begin(); task != tasks.end(); task++) {
IK_QTask *qtask = *task;
if (qtask->Primary()) {
qtask->SetId(primary_size);
primary_size += qtask->Size();
primary_weight += qtask->Weight();
primary++;
}
else {
qtask->SetId(secondary_size);
secondary_size += qtask->Size();
secondary_weight += qtask->Weight();
secondary++;
}
}
if (primary_size == 0 || FuzzyZero(primary_weight))
return false;
m_secondary_enabled = (secondary > 0);
// rescale weights of tasks to sum up to 1
double primary_rescale = 1.0 / primary_weight;
double secondary_rescale;
if (FuzzyZero(secondary_weight))
secondary_rescale = 0.0;
else
secondary_rescale = 1.0 / secondary_weight;
for (task = tasks.begin(); task != tasks.end(); task++) {
IK_QTask *qtask = *task;
if (qtask->Primary())
qtask->SetWeight(qtask->Weight() * primary_rescale);
else
qtask->SetWeight(qtask->Weight() * secondary_rescale);
}
// set matrix sizes
m_jacobian.ArmMatrices(num_dof, primary_size);
if (secondary > 0)
m_jacobian_sub.ArmMatrices(num_dof, secondary_size);
// set dof weights
int i;
for (seg = m_segments.begin(); seg != m_segments.end(); seg++)
for (i = 0; i < (*seg)->NumberOfDoF(); i++)
m_jacobian.SetDoFWeight((*seg)->DoFId() + i, (*seg)->Weight(i));
return true;
}
void IK_QJacobianSolver::SetPoleVectorConstraint(
IK_QSegment *tip, Vector3d &goal, Vector3d &polegoal, float poleangle, bool getangle)
{
m_poleconstraint = true;
m_poletip = tip;
m_goal = goal;
m_polegoal = polegoal;
m_poleangle = (getangle) ? 0.0f : poleangle;
m_getpoleangle = getangle;
}
void IK_QJacobianSolver::ConstrainPoleVector(IK_QSegment *root, std::list<IK_QTask *> &tasks)
{
// this function will be called before and after solving. calling it before
// solving gives predictable solutions by rotating towards the solution,
// and calling it afterwards ensures the solution is exact.
if (!m_poleconstraint)
return;
// disable pole vector constraint in case of multiple position tasks
std::list<IK_QTask *>::iterator task;
int positiontasks = 0;
for (task = tasks.begin(); task != tasks.end(); task++)
if ((*task)->PositionTask())
positiontasks++;
if (positiontasks >= 2) {
m_poleconstraint = false;
return;
}
// get positions and rotations
root->UpdateTransform(m_rootmatrix);
const Vector3d rootpos = root->GlobalStart();
const Vector3d endpos = m_poletip->GlobalEnd();
const Matrix3d &rootbasis = root->GlobalTransform().linear();
// construct "lookat" matrices (like gluLookAt), based on a direction and
// an up vector, with the direction going from the root to the end effector
// and the up vector going from the root to the pole constraint position.
Vector3d dir = normalize(endpos - rootpos);
Vector3d rootx = rootbasis.col(0);
Vector3d rootz = rootbasis.col(2);
Vector3d up = rootx * cos(m_poleangle) + rootz * sin(m_poleangle);
// in post, don't rotate towards the goal but only correct the pole up
Vector3d poledir = (m_getpoleangle) ? dir : normalize(m_goal - rootpos);
Vector3d poleup = normalize(m_polegoal - rootpos);
Matrix3d mat, polemat;
mat.row(0) = normalize(dir.cross(up));
mat.row(1) = mat.row(0).cross(dir);
mat.row(2) = -dir;
polemat.row(0) = normalize(poledir.cross(poleup));
polemat.row(1) = polemat.row(0).cross(poledir);
polemat.row(2) = -poledir;
if (m_getpoleangle) {
// we compute the pole angle that to rotate towards the target
m_poleangle = angle(mat.row(1), polemat.row(1));
double dt = rootz.dot(mat.row(1) * cos(m_poleangle) + mat.row(0) * sin(m_poleangle));
if (dt > 0.0)
m_poleangle = -m_poleangle;
// solve again, with the pole angle we just computed
m_getpoleangle = false;
ConstrainPoleVector(root, tasks);
}
else {
// now we set as root matrix the difference between the current and
// desired rotation based on the pole vector constraint. we use
// transpose instead of inverse because we have orthogonal matrices
// anyway, and in case of a singular matrix we don't get NaN's.
Affine3d trans;
trans.linear() = polemat.transpose() * mat;
trans.translation() = Vector3d(0, 0, 0);
m_rootmatrix = trans * m_rootmatrix;
}
}
bool IK_QJacobianSolver::UpdateAngles(double &norm)
{
// assign each segment a unique id for the jacobian
std::vector<IK_QSegment *>::iterator seg;
IK_QSegment *qseg, *minseg = NULL;
double minabsdelta = 1e10, absdelta;
Vector3d delta, mindelta;
bool locked = false, clamp[3];
int i, mindof = 0;
// here we check if any angle limits were violated. angles whose clamped
// position is the same as it was before, are locked immediate. of the
// other violation angles the most violating angle is rememberd
for (seg = m_segments.begin(); seg != m_segments.end(); seg++) {
qseg = *seg;
if (qseg->UpdateAngle(m_jacobian, delta, clamp)) {
for (i = 0; i < qseg->NumberOfDoF(); i++) {
if (clamp[i] && !qseg->Locked(i)) {
absdelta = fabs(delta[i]);
if (absdelta < IK_EPSILON) {
qseg->Lock(i, m_jacobian, delta);
locked = true;
}
else if (absdelta < minabsdelta) {
minabsdelta = absdelta;
mindelta = delta;
minseg = qseg;
mindof = i;
}
}
}
}
}
// lock most violating angle
if (minseg) {
minseg->Lock(mindof, m_jacobian, mindelta);
locked = true;
if (minabsdelta > norm)
norm = minabsdelta;
}
if (locked == false)
// no locking done, last inner iteration, apply the angles
for (seg = m_segments.begin(); seg != m_segments.end(); seg++) {
(*seg)->UnLock();
(*seg)->UpdateAngleApply();
}
// signal if another inner iteration is needed
return locked;
}
bool IK_QJacobianSolver::Solve(IK_QSegment *root,
std::list<IK_QTask *> tasks,
const double,
const int max_iterations)
{
float scale = ComputeScale();
bool solved = false;
// double dt = analyze_time();
Scale(scale, tasks);
ConstrainPoleVector(root, tasks);
root->UpdateTransform(m_rootmatrix);
// iterate
for (int iterations = 0; iterations < max_iterations; iterations++) {
// update transform
root->UpdateTransform(m_rootmatrix);
std::list<IK_QTask *>::iterator task;
// compute jacobian
for (task = tasks.begin(); task != tasks.end(); task++) {
if ((*task)->Primary())
(*task)->ComputeJacobian(m_jacobian);
else
(*task)->ComputeJacobian(m_jacobian_sub);
}
double norm = 0.0;
do {
// invert jacobian
try {
m_jacobian.Invert();
if (m_secondary_enabled)
m_jacobian.SubTask(m_jacobian_sub);
}
catch (...) {
fprintf(stderr, "IK Exception\n");
return false;
}
// update angles and check limits
} while (UpdateAngles(norm));
// unlock segments again after locking in clamping loop
std::vector<IK_QSegment *>::iterator seg;
for (seg = m_segments.begin(); seg != m_segments.end(); seg++)
(*seg)->UnLock();
// compute angle update norm
double maxnorm = m_jacobian.AngleUpdateNorm();
if (maxnorm > norm)
norm = maxnorm;
// check for convergence
if (norm < 1e-3 && iterations > 10) {
solved = true;
break;
}
}
if (m_poleconstraint)
root->PrependBasis(m_rootmatrix.linear());
Scale(1.0f / scale, tasks);
// analyze_add_run(max_iterations, analyze_time()-dt);
return solved;
}
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