btHingeConstraint::enableAngularMotor doubt

[bindumol]

Hi,

I have rigid body which is attached to the physics world using a btHingeConstraint. I have applied a motor torque using enableAngularMotor function. Can anybody tell me how to stop the rotation? The below code is not stopping the rotation.

float targetVelocity = 0.f;
float maxMotorImpulse = 0.0f;
hinge->enableAngularMotor(false, targetVelocity,maxMotorImpulse);


regards
Bindumol

[ola]

Seems you are setting the maximum motor impulse to zero. The motor won't be able to stop it's rotation when the max impulse it may use is zero, so increase maxMotorImpulse to something > 0.0. As for what value to choose, you'll have to experiment a bit, it depends on how strong your motor is supposed to be.

Best regards,
Ola

[Erwin Coumans]

We will double-check the hinge motor contribution.

In the meanwhile, can you try out the btSliderConstraint? In the latest Bullet version it has a linear and angular motor, and you can configure it to be a hinge.

Thanks for the feedback,
Erwin

[bindumol]

Hi,
Thanks for the reply...Now i can stop the rotation by giving high impulse to the hingemotor.
I tries it with the btSliderConstraint but i didn't get the rotation like a hinge constraint...can u help me ...


spSlider = new btSliderConstraint(*RigidBody1,*fixedbody,Transform,Transform1,false);
spSlider->setLowerLinLimit(-15.0F);
spSlider->setUpperLinLimit(-5.0F);
spSlider->setLowerAngLimit(0);
spSlider->setUpperAngLimit(100);
World->addConstraint(spSlider, true);

Thanks
Bindumol

[rponomarev]

Hello,

Do you use the 2.69 version of Bullet? Earlier vesions do not have motors in the btSliderConstraint
To enable rotatiolal motor use code like

spSlider = new btSliderConstraint(*RigidBody1,*fixedbody,Transform,Transform1,false);
spSlider->setLowerLinLimit(-15.0F);
spSlider->setUpperLinLimit(-5.0F);
spSlider->setLowerAngLimit(0);
spSlider->setUpperAngLimit(100);


spSlider->setPoweredAngMotor(true);
spSlider->setMaxAngMotorForce(10.0);
spSlider->setTargetAngMotorVelocity(1.0);


World->addConstraint(spSlider, true);

Hope this will help,
Roman

[bindumol]

hi,
Thanks for the reply...one more doubt...how i can make an angular rotation using hinge by giving the values as degrees...is it possible?

[eddybox]

There's an example of how to set a target angle in MotorDemo.cpp. See enableAngularMotor(...) and the code just above it.
(Though I agree it would be nice to provide this as a service in the constraint class.)

Cheers,
Eddy

[bindumol]

Hi,
If i am using the hinge motor then also i am having the problem as to stop the motor within nthe limit & to avoid the swining of the motor within the limit.How it can possible? Is it possible by using the setDamping to the body.