Calculating torque in LE?

[Andy Gilbert]

Just wondering if LE has any nice commands for calculating the torque generated by acting forces?

 

Thanks

Andy

[TylerH]

I think GetBodyTorque?

[Andy Gilbert]

Hi tyler, Cant find that in the wiki? Only:

 

4.4 Check state (Get...)

4.4.1 GetBodyVelocity

4.4.2 GetBodyOmega <---- ???

4.4.3 GetBodyMass

 

Andy

[Canardia]

GetBodyOmega() should be called actually GetBodyTorque(). The term Omega makes really no sense here, as it's only the angle of the force perpendicular to the radius at where the force is applied from the center of the pivot, which should always result in sin(Omega)=1.0.

Torque = Tau = r * F * sin(Omega).

However, using angles in mathematics and physics is obsolete, and you should use vectors only:

Torque = Tau = rvec x Fvec

[Andy Gilbert]

Yeh thats why i marked it with a ?? as i thought it was but was confused with its name.

 

Ok, so ill use that.

 

Cheers Mika.

[TylerH]

Lumooja has the right point here.

 

I knew of GetBodyOmega, which is just angular velocity. GetBodyTorque should be implemented such as he said.

[Josh]

A get force or get torque command would only return the force that has been applied by the user since the previous physics update. It does not correspond to velocity or omega (angular velocity).

[Canardia]

Well, it's as simple as renaming the GetBodyOmega() to GetBodyAngularVelocity(). Currently it returns the angular velocity anyway (a Vec3), and not the Omega (which is the "1/cos(tan(wrong direction of the force))" or whatever the anti-sin(Omega) is), also a Vec3).

[Josh]

Angular velocity is commonly referred to as omega:

http://en.wikipedia....ngular_velocity

[Canardia]

I see. It seems physicians are using the same name (Omega) for two different things. In velocity formulas it seems to be used for the angular speed, but in torque formulas it's used as angle of the force (or like I like to say: "1-wrongness of the direction of the force"):

http://en.wikipedia.org/wiki/Torque

[Josh]

Physicists, not physicians.

[Canardia]

Oh, american/british english strikes again

In international english it is related to physics, like magician is related to magic, canardian is related to canards, or norwegian is related to norway.

Both the role of the physician and the meaning of the word itself vary significantly around the world.

In international english, we call those who (often unsuccesfully) experiment with human bodies, doctors. They use doctrines based on mutual feelings and mutual information, without actually knowing how the human body or its DNA works. It's like a computer programmer who has no clue what processors, bits and bytes are, and just copy pastes code since it worked for someone else in a similar situation