void Gl1_Membrane::go(const shared_ptr<Shape>& sh, const Vector3r& shift, bool wire2, const GLViewInfo& viewInfo){
Gl1_Facet::go(sh,shift,/*don't force wire rendering*/ wire2,viewInfo);
if(Renderer::fastDraw) return;
Membrane& ff=sh->cast<Membrane>();
if(!ff.hasRefConf()) return;
if(node){
Renderer::setNodeGlData(ff.node,false/*set refPos only for the first time*/);
Renderer::renderRawNode(ff.node);
if(ff.node->rep) ff.node->rep->render(ff.node,&viewInfo);
#ifdef MEMBRANE_DEBUG_ROT
// show what Membrane thinks the orientation of nodes is - render those midway
if(ff.currRot.size()==3){
for(int i:{0,1,2}){
shared_ptr<Node> n=make_shared<Node>();
n->pos=ff.node->pos+.5*(ff.nodes[i]->pos-ff.node->pos);
n->ori=(ff.currRot[i]*ff.node->ori.conjugate()).conjugate();
Renderer::renderRawNode(n);
}
}
#endif
}
// draw everything in in local coords now
glPushMatrix();
if(!Renderer::scaleOn){
// without displacement scaling, local orientation is easy
GLUtils::setLocalCoords(ff.node->pos,ff.node->ori);
} else {
/* otherwise compute scaled orientation such that
* +x points to the same point on the triangle (in terms of angle)
* +z is normal to the facet in the GL space
*/
Real phi0=atan2(ff.refPos[1],ff.refPos[0]);
Vector3r C=ff.getGlCentroid();
Matrix3r rot;
rot.row(2)=ff.getGlNormal();
rot.row(0)=(ff.getGlVertex(0)-C).normalized();
rot.row(1)=rot.row(2).cross(rot.row(0));
Quaternionr ori=AngleAxisr(phi0,Vector3r::UnitZ())*Quaternionr(rot);
GLUtils::setLocalCoords(C,ori.conjugate());
}
if(refConf){
glColor3v(refColor);
glLineWidth(refWd);
glBegin(GL_LINE_LOOP);
for(int i:{0,1,2}) glVertex3v(Vector3r(ff.refPos[2*i],ff.refPos[2*i+1],0));
glEnd();
}
if(uScale!=0){
glLineWidth(uWd);
for(int i:{0,1,2}) drawLocalDisplacement(ff.refPos.segment<2>(2*i),uScale*ff.uXy.segment<2>(2*i),uRange,uSplit,arrows?1:0,uWd);
}
if(relPhi!=0 && ff.hasBending()){
glLineWidth(phiWd);
for(int i:{0,1,2}) drawLocalDisplacement(ff.refPos.segment<2>(2*i),relPhi*viewInfo.sceneRadius*ff.phiXy.segment<2>(2*i),phiRange,phiSplit,arrows?2:0,phiWd
#ifdef MEMBRANE_DEBUG_ROT
, relPhi*viewInfo.sceneRadius*ff.drill[i] /* show the out-of-plane component */
#endif
);
}
glPopMatrix();
}
/*
Generic function to compute L3Geom (with colinear points), used for {sphere,facet,wall}+sphere contacts now
*/
void Ig2_Sphere_Sphere_L3Geom::handleSpheresLikeContact(const shared_ptr<Interaction>& I, const State& state1, const State& state2, const Vector3r& shift2, bool is6Dof, const Vector3r& normal, const Vector3r& contPt, Real uN, Real r1, Real r2){
// create geometry
if(!I->geom){
if(is6Dof) I->geom=shared_ptr<L6Geom>(new L6Geom);
else I->geom=shared_ptr<L3Geom>(new L3Geom);
L3Geom& g(I->geom->cast<L3Geom>());
g.contactPoint=contPt;
g.refR1=r1; g.refR2=r2;
g.normal=normal;
// g.trsf.setFromTwoVectors(Vector3r::UnitX(),g.normal); // quaternion just from the X-axis; does not seem to work for some reason?!
const Vector3r& locX(g.normal);
// initial local y-axis orientation, in the xz or xy plane, depending on which component is larger to avoid singularities
Vector3r locY=normal.cross(abs(normal[1])<abs(normal[2])?Vector3r::UnitY():Vector3r::UnitZ()); locY-=locX*locY.dot(locX); locY.normalize();
Vector3r locZ=normal.cross(locY);
#ifdef L3_TRSF_QUATERNION
Matrix3r trsf; trsf.row(0)=locX; trsf.row(1)=locY; trsf.row(2)=locZ;
g.trsf=Quaternionr(trsf); // from transformation matrix
#else
g.trsf.row(0)=locX; g.trsf.row(1)=locY; g.trsf.row(2)=locZ;
#endif
g.u=Vector3r(uN,0,0); // zero shear displacement
if(distFactor<0) g.u0[0]=uN;
// L6Geom::phi is initialized to Vector3r::Zero() automatically
//cerr<<"Init trsf=\n"<<g.trsf<<endl<<"locX="<<locX<<", locY="<<locY<<", locZ="<<locZ<<endl;
return;
}
// update geometry
/* motion of the conctact consists in rigid motion (normRotVec, normTwistVec) and mutual motion (relShearDu);
they are used to update trsf and u
*/
L3Geom& g(I->geom->cast<L3Geom>());
const Vector3r& currNormal(normal); const Vector3r& prevNormal(g.normal);
// normal rotation vector, between last steps
Vector3r normRotVec=prevNormal.cross(currNormal);
// contrary to what ScGeom::precompute does now (r2486), we take average normal, i.e. .5*(prevNormal+currNormal),
// so that all terms in the equation are in the previous mid-step
// the re-normalization might not be necessary for very small increments, but better do it
Vector3r avgNormal=(approxMask&APPROX_NO_MID_NORMAL) ? prevNormal : .5*(prevNormal+currNormal);
if(!(approxMask&APPROX_NO_RENORM_MID_NORMAL) && !(approxMask&APPROX_NO_MID_NORMAL)) avgNormal.normalize(); // normalize only if used and if requested via approxMask
// twist vector of the normal from the last step
Vector3r normTwistVec=avgNormal*scene->dt*.5*avgNormal.dot(state1.angVel+state2.angVel);
// compute relative velocity
// noRatch: take radius or current distance as the branch vector; see discussion in ScGeom::precompute (avoidGranularRatcheting)
Vector3r c1x=((noRatch && !r1>0) ? ( r1*normal).eval() : (contPt-state1.pos).eval()); // used only for sphere-sphere
Vector3r c2x=(noRatch ? (-r2*normal).eval() : (contPt-state2.pos+shift2).eval());
//Vector3r state2velCorrected=state2.vel+(scene->isPeriodic?scene->cell->intrShiftVel(I->cellDist):Vector3r::Zero()); // velocity of the second particle, corrected with meanfield velocity if necessary
//cerr<<"correction "<<(scene->isPeriodic?scene->cell->intrShiftVel(I->cellDist):Vector3r::Zero())<<endl;
Vector3r relShearVel=(state2.vel+state2.angVel.cross(c2x))-(state1.vel+state1.angVel.cross(c1x));
// account for relative velocity of particles in different cell periods
if(scene->isPeriodic) relShearVel+=scene->cell->intrShiftVel(I->cellDist);
relShearVel-=avgNormal.dot(relShearVel)*avgNormal;
Vector3r relShearDu=relShearVel*scene->dt;
/* Update of quantities in global coords consists in adding 3 increments we have computed; in global coords (a is any vector)
1. +relShearVel*scene->dt; // mutual motion of the contact
2. -a.cross(normRotVec); // rigid rotation perpendicular to the normal
3. -a.cross(normTwistVec); // rigid rotation parallel to the normal
*/
// compute current transformation, by updating previous axes
// the X axis can be prescribed directly (copy of normal)
// the mutual motion on the contact does not change transformation
#ifdef L3_TRSF_QUATERNION
const Matrix3r prevTrsf(g.trsf.toRotationMatrix());
Quaternionr prevTrsfQ(g.trsf);
#else
const Matrix3r prevTrsf(g.trsf); // could be reference perhaps, but we need it to compute midTrsf (if applicable)
#endif
Matrix3r currTrsf; currTrsf.row(0)=currNormal;
for(int i=1; i<3; i++){
currTrsf.row(i)=prevTrsf.row(i)-prevTrsf.row(i).cross(normRotVec)-prevTrsf.row(i).cross(normTwistVec);
}
#ifdef L3_TRSF_QUATERNION
Quaternionr currTrsfQ(currTrsf);
if((scene->iter % trsfRenorm)==0 && trsfRenorm>0) currTrsfQ.normalize();
#else
if((scene->iter % trsfRenorm)==0 && trsfRenorm>0){
#if 1
currTrsf.row(0).normalize();
currTrsf.row(1)-=currTrsf.row(0)*currTrsf.row(1).dot(currTrsf.row(0)); // take away y projected on x, to stabilize numerically
currTrsf.row(1).normalize();
currTrsf.row(2)=currTrsf.row(0).cross(currTrsf.row(1));
currTrsf.row(2).normalize();
#else
currTrsf=Matrix3r(Quaternionr(currTrsf).normalized());
#endif
#ifdef YADE_DEBUG
if(abs(currTrsf.determinant()-1)>.05){
LOG_ERROR("##"<<I->getId1()<<"+"<<I->getId2()<<", |trsf|="<<currTrsf.determinant());
g.trsf=currTrsf;
throw runtime_error("Transformation matrix far from orthonormal.");
}
#endif
}
#endif
/* Previous local trsf u'⁻ must be updated to current u'⁰. We have transformation T⁻ and T⁰,
δ(a) denotes increment of a as defined above. Two possibilities:
1. convert to global, update, convert back: T⁰(T⁻*(u'⁻)+δ(T⁻*(u'⁻))). Quite heavy.
2. update u'⁻ straight, using relShearVel in local coords; since relShearVel is computed
at (t-Δt/2), we would have to find intermediary transformation (same axis, half angle;
the same as slerp at t=.5 between the two).
This could be perhaps simplified by using T⁰ or T⁻ since they will not differ much,
but it would have to be verified somehow.
*/
// if requested via approxMask, just use prevTrsf
#ifdef L3_TRSF_QUATERNION
Quaternionr midTrsf=(approxMask&APPROX_NO_MID_TRSF) ? prevTrsfQ : prevTrsfQ.slerp(.5,currTrsfQ);
#else
Quaternionr midTrsf=(approxMask&APPROX_NO_MID_TRSF) ? Quaternionr(prevTrsf) : Quaternionr(prevTrsf).slerp(.5,Quaternionr(currTrsf));
#endif
//cerr<<"prevTrsf=\n"<<prevTrsf<<", currTrsf=\n"<<currTrsf<<", midTrsf=\n"<<Matrix3r(midTrsf)<<endl;
// updates of geom here
// midTrsf*relShearVel should have the 0-th component (approximately) zero -- to be checked
g.u+=midTrsf*relShearDu;
//cerr<<"midTrsf=\n"<<midTrsf<<",relShearDu="<<relShearDu<<", transformed "<<midTrsf*relShearDu<<endl;
g.u[0]=uN; // this does not have to be computed incrementally
#ifdef L3_TRSF_QUATERNION
g.trsf=currTrsfQ;
#else
g.trsf=currTrsf;
#endif
// GenericSpheresContact
g.refR1=r1; g.refR2=r2;
g.normal=currNormal;
g.contactPoint=contPt;
if(is6Dof){
// update phi, from the difference of angular velocities
// the difference is transformed to local coord using the midTrsf transformation
// perhaps not consistent when spheres have different radii (depends how bending moment is computed)
I->geom->cast<L6Geom>().phi+=midTrsf*(scene->dt*(state2.angVel-state1.angVel));
}
};