void static calcRotEqs(const Rod& r, const VecXe& rot, const std::vector<Vec3e>& curveBinorm,
VecXe& grad, std::vector<Triplet>& triplets) {
Eigen::Matrix<real, 2, 2> J;
J << 0.0, -1.0, 1.0, 0.0;
for (int i=1; i<r.numEdges()-1; i++) {
Vec3e m1 = cos(rot(i)) * r.next().u[i] + sin(rot(i)) * r.next().v(i);
Vec3e m2 = -sin(rot(i)) * r.next().u[i] + cos(rot(i)) * r.next().v(i);
Vec2e curvePrev(curveBinorm[i-1].dot(m2), -curveBinorm[i-1].dot(m1)); // omega ^i _i
Vec2e curveNext(curveBinorm[i].dot(m2), -curveBinorm[i].dot(m1)); // omega ^i _i+1
real dWprev = 1.0 / r.restVoronoiLength(i) *
curvePrev.dot(J * r.getCS()[i].bendMat() * (curvePrev - r.restCurveNext(i)));
real dWnext = 1.0 / r.restVoronoiLength(i+1) *
curveNext.dot(J * r.getCS()[i+1].bendMat() * (curveNext - r.restCurvePrev(i+1)));
real twistPrev = rot(i) - rot(i-1) + r.next().refTwist(i);
real twistNext = rot(i+1) - rot(i) + r.next().refTwist(i+1);
grad(i-1) = -(dWprev + dWnext + 2.0 * r.getCS()[i].twistCoeff() *
(twistPrev/r.restVoronoiLength(i) - twistNext/r.restVoronoiLength(i+1)));
real hess = 2.0*(r.getCS()[i].twistCoeff()/r.restVoronoiLength(i) +
r.getCS()[i+1].twistCoeff()/r.restVoronoiLength(i+1));
hess += 1.0 / r.restVoronoiLength(i) *
(curvePrev.dot(J.transpose() * r.getCS()[i].bendMat() * J * curvePrev)
- curvePrev.dot(r.getCS()[i].bendMat() * (curvePrev - r.restCurveNext(i))));
hess += 1.0 /r.restVoronoiLength(i+1) *
(curveNext.dot(J.transpose() * r.getCS()[i+1].bendMat() * J * curveNext)
- curveNext.dot(r.getCS()[i+1].bendMat() * (curveNext - r.restCurvePrev(i+1))));
triplets.push_back(Triplet(i-1, i-1, hess));
}
}
void RodSoundApp::loadDefaultRod(int numPoints) {
if (r) delete r;
Vec3e start = Vec3e(0.0, 1.9144, 0.0); // Vec3e(0.5, 1.0, 0.5);
Vec3e end = Vec3e(0.0, 1.0, 0.0); // start + (Vec3e(-1.0, -1.0, -1.0).normalized() * 0.6069);
// 1ft. = 0.3048m
// 2ft. = 0.6069m
// 3ft. = 0.9144m
Vec3e u = (end-start).cross(Vec3e(0.0, 0.1, 0.0)).normalized();
if (u.hasNaN() || u.norm() < 0.95) {
u << 1.0, 0.0, 0.0;
}
VecXe rodPos(3*numPoints);
for(int i=0; i < numPoints; i++) {
real t = ((real) i) / (real) (numPoints -1);
rodPos.segment<3>(3*i) = (1-t)*start + t*end;
}
eyePos = Vec3c(5.0, 1.5, 0.0);
targetPos = Vec3c(0.0, 1.5, 0.0);
cam.lookAt(eyePos, targetPos, Vec3c(0.0, 1.0, 0.0));
// FIXME: assumes circular cylindrical rod of default radius
real totalMass = constants::radius * constants::radius * constants::pi * (start - end).norm() * constants::rhoRod;
real massPerPoint = totalMass / numPoints;
VecXe mass = VecXe::Constant(numPoints, massPerPoint);
r = new Rod(rodPos, u, &mass);
real l = (start - end).norm();
real kappa = sqrt(r->youngsModulus * r->getCS()[0].areaMoment()(0, 0) /
(constants::rhoRod * r->getCS()[0].area() * l * l * l * l));
std::cout << "kappa: " << kappa << "\n";
real h = l / (numPoints-1);
real k = 1.0 / (44100*multiSample);
real mu = kappa * k / (h * h);
std::cout << "mu: " << mu << "\n";
real fmax = asin(2.0 * mu) / (constants::pi * k);
std::cout << "fmax: " << fmax << "\n";
/*
real cb = std::pow(constants::youngsModulus * r->getCS()[0].areaMoment()(0, 0) / constants::rhoRod / r->getCS()[0].area(), 0.25);
real cbHigh = cb * 141.4;
real cbLow = cb * 4.47;
real dx = (start - end).norm() / (numPoints - 1.0);
std::cout << "Min timestep: " << dx / cbHigh << "\n";
*/
}
IMEXIntegrator::IMEXIntegrator(std::vector<RodEnergy*>& energies, Rod& r) :
Integrator(r, energies) {
// Fill hess base
std::vector<Triplet> triplets;
for (int i=1; i < r.numEdges()-1; i++) {
if (i > 1) {
triplets.push_back(Triplet(i-1, i-2, -2.0*r.getCS()[i].twistCoeff()/r.restVoronoiLength(i)));
}
if (i < r.numEdges()-2) {
triplets.push_back(Triplet(i-1, i, -2.0*r.getCS()[i+1].twistCoeff()/r.restVoronoiLength(i+1)));
}
}
hessBase = Eigen::SparseMatrix<real>(r.numEdges()-2, r.numEdges()-2);
hessBase.setFromTriplets(triplets.begin(), triplets.end());
}
void RodSoundApp::update()
{
if (!running) return;
if (curSample % 5000 == 0 && curSample != 0 && c.getTicks() % multiSample == 0) {
std::cout << curSample << " / " << BufferSize << " (" << (curSample*100.0)/BufferSize << "%)\n";
PROFILER_PRINT_ELAPSED();
PROFILER_RESET_ALL();
std::cout << "\n";
}
if (curSample >= BufferSize || stopNow) { // We're done!
sampleBuffer[0] = 0.0; // To prevent the click of forces suddenly being applied
double max = 0;
for (int i=0; i<BufferSize; i++) {
max = std::max(max, std::fabs(sampleBuffer[i]));
}
std::cout << "Max1: " << max << "\n";
uint16_t buffer[BufferSize];
for (int i=0; i<BufferSize; i++) {
buffer[i] = toSample(sampleBuffer[i], max);
}
writeWAVData((constants::ResultPath+"result.wav").data(), buffer,
curSample * sizeof(uint16_t), SampleRate, 1);
sampleBuffer2[0] = 0.0;
max = 0;
for (int i=0; i<BufferSize; i++) {
max = std::max(max, std::fabs(sampleBuffer2[i]));
}
std::cout << "Max2: " << max << "\n";
for (int i=0; i<BufferSize; i++) {
buffer[i] = toSample(sampleBuffer2[i], max);
}
writeWAVData((constants::ResultPath+"result2.wav").data(), buffer,
curSample * sizeof(uint16_t), SampleRate, 1);
sampleBuffer3[0] = 0.0;
max = 0;
for (int i=0; i<BufferSize; i++) {
max = std::max(max, std::fabs(sampleBuffer3[i]));
}
std::cout << "Max3: " << max << "\n";
for (int i=0; i<BufferSize; i++) {
buffer[i] = toSample(sampleBuffer3[i], max);
}
writeWAVData((constants::ResultPath+"result3.wav").data(), buffer,
curSample * sizeof(uint16_t), SampleRate, 1);
fe.writeMPEG("result");
std::cout << "Total simulation time: " << app::getElapsedSeconds() << "\n"; // FIXME: This is inaccurate
running = false;
return;
}
PROFILER_START("Update");
c.suggestTimestep(1.0 / (real) SampleRate / multiSample);
// FIXME: Normally the frame exporter would suggest a timestep, but this interferes with the audio
// recording, as it assumes all timesteps are 1/SampleRate. However, any error the frame exporter
// experiences is small since 1/60 >> 1/SampleRate.
// fe.suggestTimestep(c);
Vec3e mp;
if (isMouseDown) mp << mousePosition.x, mousePosition.y, mousePosition.z;
mouseSpring->setMouse(mp, isMouseDown);
if (!integrator->integrate(c)) throw;
/// Update Bishop frame
r->next().updateReferenceFrames(r->cur());
// Sound Calculations
if (c.getTicks() % multiSample == 0) {
real sample = 0;
real sample2 = 0;
real avgX = 0;
VecXe jerkVec = r->next().dVel - r->cur().dVel;
for (int i=1; i<r->numCPs()-1; i++) {
avgX += r->next().VEL(i).x();
// Calculate jerk
Vec3e jerk = jerkVec.segment<3>(3*i);
// Project jerk to transverse plane
Vec3e tPlaneNormal = (r->next().edge(i-1) + r->next().edge(i)).normalized();
jerk = jerk - jerk.dot(tPlaneNormal) * tPlaneNormal; // Vector rejection of jerk from tPlaneNormal
/*
real m0 = r->restVoronoiLength(i)*constants::pi*r->radius()*r->radius()*constants::rhoAir;
// Rotation to align system so that the cylinder is coaxial with the z-axis
Eigen::Quaternion<real> q = Eigen::Quaternion<real>::FromTwoVectors(tPlaneNormal, Vec3e(0, 0, 1));
Vec3e rotJerk = q * jerk;
rotJerk = rotJerk.cwiseProduct(Vec3e(2.0*m0, 2.0*m0, m0));
// Calculate sample contribution
Vec3e earVec = CtoE(eyePos) - r->next().points[i].pos;
sample += (q * earVec).dot(rotJerk) / (4.0 * constants::pi * constants::cAir * earVec.dot(earVec));
earVec = ear2Pos - r->next().points[i].pos;
sample2 += (q * earVec).dot(rotJerk) / (4.0 * constants::pi * constants::cAir * earVec.dot(earVec));
*/
Vec3e earVec = CtoE(eyePos) - r->next().POS(i);
// Calculate sample contribution
sample += r->getCS()[i].calcSample(earVec, jerk);
earVec = ear2Pos - r->next().POS(i);
sample2 += r->getCS()[i].calcSample(earVec, jerk);
}
avgX = avgX/(r->numCPs()-2);
sampleBuffer[curSample] = sample;
sampleBuffer2[curSample] = sample2;
sampleBuffer3[curSample] = r->next().VEL(r->numCPs()/2).x() - avgX;
curSample++;
}
// Swap Rods
r->swapRods();
c.increment();
PROFILER_STOP("Update");
}