Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed: https://answers.launchpad.net/yade/+question/686076 Status: Answered => Solved yang yi confirmed that the question is solved: Thanks Jan Stránský, that solved my question. -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed: https://answers.launchpad.net/yade/+question/686076 Jan Stránský proposed the following answer: 1) you have to change velocity directly of RotationEngine (see my previous anwer #5). This way, you change a global velocity variable, byt RotationEngine has its copy and the change has no effect on it. 2) again see #5, should be q = Quaternion(rotationAxis, angVel* O.dt) # without any AngleAxis stuff cheers Jan -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed: https://answers.launchpad.net/yade/+question/686076 yang yi posted a new comment: Thank you very much!! Jan Stránský Now I have two problem (1) for using RotationEngine, I hope the following code can change the direction of the plane by the PyRunner function ChangeVelocity, but it cannot, the value of Velocity can be changed, but the plane still Rotation as the initial speed and direction. velocity = 10 def ChangeVelocity(): global velocity velocity = -1 * velocity O.engines = [ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(), Bo1_Facet_Aabb()]), InteractionLoop( # handle sphere+sphere and facet+sphere collisions [Ig2_Sphere_Sphere_ScGeom(), Ig2_Facet_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_FrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack()]), # [Ip2_ViscElMat_ViscElMat_ViscElPhys()], # [Law2_ScGeom_ViscElPhys_Basic()]), NewtonIntegrator(gravity=(-9.8, 0, 0), damping=0.001, label='down'), RotationEngine(rotationAxis=(0, 0, 1), angularVelocity=velocity, rotateAroundZero=True, zeroPoint=(0, 0, 0)), PyRunner(command="ChangeVelocity()", iterPeriod=10) ] (2) The problem of transform the C++ code of RotationEngine to python, I hope I can control the rotation velocity of the plane. def myRotation(): ZeroPos = Vector3(1, 1, 0) rotationAxis = Vector3(0, 0, 1) angVel = 10 for i in IDGround: O.bodies[i].state.angVel += rotationAxis * angVel l = O.bodies[i].state.pos - ZeroPos q = Quaternion(AngleAxis(rotationAxis, angVel* O.dt)) # q = Quaternion(rotationAxis, angVel * O.dt) newp = q*l + ZeroPos O.bodies[i].state.vel += (newp - O.bodies[i].state.pos)/O.dt O.engines = [ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(), Bo1_Facet_Aabb()]), InteractionLoop( # handle sphere+sphere and facet+sphere collisions [Ig2_Sphere_Sphere_ScGeom(), Ig2_Facet_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_FrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack()]), # [Ip2_ViscElMat_ViscElMat_ViscElPhys()], # [Law2_ScGeom_ViscElPhys_Basic()]), NewtonIntegrator(gravity=(-9.8, 0, 0), damping=0.001, label='down'), PyRunner(command="myRotation()",iterPeriod=40) # RotationEngine(rotationAxis=(0, 0, 1), angularVelocity=velocity, rotateAroundZero=True, zeroPoint=(0, 0, 0)), # PyRunner(command="ChangeVelocity()", iterPeriod=10) ] I can find the "AngleAxis", and the error is "name 'AngleAxis' is not defined". The above code is follow the C++ in the KinematicEngines.cpp. I don't know if the transform is correct or not. Please help me,Thank you very much, -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed: https://answers.launchpad.net/yade/+question/686076 Jan Stránský proposed the following answer: > However, the speed I cound not change during simulation. > But the velocity can not changed. Why? Please always try to be specific. Did you get an error? What error? The velocity did not change? How did you investigate it? ... ### RotationEngine(..., label="rotEngine") ... def myRotation(): rotEngine.angularVelocity = whatever ### Concerning axis-angle, in Python Quaternion can be constructed directly from axis and angle: C++: Quaternionr q(AngleAxisr(angularVelocity*scene->dt,rotationAxis)); Python: q = Quaternion(rotationAxis,angularVelocity*O.dt) cheers Jan -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed:
https://answers.launchpad.net/yade/+question/686076
yang yi posted a new comment:
Thanks for Jan Stránský (honzik) and Chareyre (bruno-chareyre-9) very much.
I tired the RotationEngine before using O.bodies[i].state.angVel . However,
the speed I cound not change during simulation. The Code is as below:
O.engines = [
。。
RotationEngine(rotationAxis=(0, 0, 1), angularVelocity= velocity,
rotateAroundZero=True, zeroPoint=(0, 0, 0))，
PyRunner(comment= "ChangeVelocity()")
]
But the velocity can not changed. So I tried the third way. Yestoday
night, I fund the function of RotationEngine in the
KinematicEngines.cpp, I understand the Chareyre's advise that the
velocity should be improved during the angleVelocity. I wirte the code
now, But I meet a new problem, I can not find the function of
AngleAxisr(). The code of RotationEngine is
void RotationEngine::apply(const vector& ids){
if (ids.size()>0) {
#ifdef YADE_OPENMP
const long size=ids.size();
#pragma omp parallel for schedule(static)
for(long i=0; ibodies->size());
Body* b=Body::byId(id,scene).get();
if(!b) continue;
b->state->angVel+=rotationAxis*angularVelocity;
if(rotateAroundZero){
const Vector3r l=b->state->pos-zeroPoint;
Quaternionr
q(AngleAxisr(angularVelocity*scene->dt,rotationAxis));
Vector3r newPos=q*l+zeroPoint;
b->state->vel+=Vector3r(newPos-b->state->pos)/scene->dt;
}
}
} else {
LOG_WARN("The list of ids is empty! Can't move any body.");
}
}
So I need to write the function AngleAxisr().
Thank you very much
Yang Yi
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Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed: https://answers.launchpad.net/yade/+question/686076 Jan Stránský posted a new comment: Just a note, 3) and 1) does the same, either "automatically" (1) or "manually" (3) Jan -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed: https://answers.launchpad.net/yade/+question/686076 Chareyre proposed the following answer: Hi, I would support 2) for the sake of performance, but there's also 3) fix myRotation() since obviously imposing rigid body motion needs to impose 'vel' too (spin*pos), not just 'angVel'. Bruno Le jeu. 21 nov. 2019 12:58, yang yi a écrit : > New question #686076 on Yade: > https://answers.launchpad.net/yade/+question/686076 > > I hope to design a plane named IDGround, it can rotate with the given > velocity, and it can be controlled to start, stop, change the speed and the > direction in the simulation. > I used the pack.sweptPolylines2gtsSurface to establish the plane, and used > the O.bodies[i].state.angVel to set the velocity. It can rotate. But the > plane is combined by two triangles, so there are two bodies in the plane, > and each of them rotates around the itself axis. I hope both of them > rotating around a given axis. How can I change my code as follows?? > Thank you very much. > > Yang Yi > > positionGround = [ > Vector3(0,0,0), > Vector3(1,0,0), > Vector3(1,1,0), > Vector3(0,1,0) > ] > Ground = pack.sweptPolylines2gtsSurface([positionGround], capStart=True, > capEnd=True) > IDGround = O.bodies.append(pack.gtsSurface2Facets(Ground, color=(1,0,1))) > > def myRotation(): > for i in IDGround: > O.bodies[i].state.angVel=(0, 0, 1) > > O.engines = [ > ForceResetter(), > InsertionSortCollider([Bo1_Sphere_Aabb(), Bo1_Facet_Aabb()]), > InteractionLoop( > # handle sphere+sphere and facet+sphere collisions > [Ig2_Sphere_Sphere_ScGeom(), Ig2_Facet_Sphere_ScGeom()], > [Ip2_FrictMat_FrictMat_FrictPhys()], > [Law2_ScGeom_FrictPhys_CundallStrack()]), > NewtonIntegrator(gravity=(-9.8, 0, 0), damping=0.001, label='down'), > PyRunner(command="myRotation()",iterPeriod=40) > # RotationEngine(rotationAxis=(0, 0, 1), angularVelocity=10.0, > rotateAroundZero=True, zeroPoint=(0, 0, 0)) > ] > > > -- > You received this question notification because your team yade-users is > an answer contact for Yade. > > ___ > Mailing list: https://launchpad.net/~yade-users > Post to : yade-users@lists.launchpad.net > Unsubscribe : https://launchpad.net/~yade-users > More help : https://help.launchpad.net/ListHelp > > > -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #686076]: Problem of Bodies rotation
Question #686076 on Yade changed: https://answers.launchpad.net/yade/+question/686076 Status: Open => Answered Jan Stránský proposed the following answer: Hello, I see 2 main options: 1) use RotationEngine 2) use a clump of facets instead of independent facets cheers Jan -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
