Real-Time Physics Simulation Forum 2012-05-03T15:39:12+00:00 https://pybullet.org/Bullet/phpBB3/app.php/feed/topic/8056 2012-05-03T15:39:12+00:00 2012-05-03T15:39:12+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=27763#p27763 <![CDATA[Re: btRaycastVehicle Wheel rotation]]> The rotation is now fine, but I think, the setup of my car is wrong :

Code: 

m_engineForce.SetRange(-1000.0, 2000.0, 0.0);   m_brake.SetRange(0.0, 100.0, 0.0);   m_steering.SetRange(-0.3, 0.3, 0.0);   m_wheelRadius = 0.31265;   m_wheelWidth = 0.215f;   m_wheelFriction = 500;   m_maxSuspensionTravelCm = 20.0f;   m_suspensionStiffness = 40.0f;   m_suspensionDamping = 2.3f;   m_suspensionCompression = 2.4;   m_rollInfluence = 0.2f;   m_suspensionRestLength = 0.1;   m_connectionHeight = -0.4;   m_chassisLenght = 4.8;   m_chassisWidth = 2;   m_chassisHeight = 1.3;   m_chassisShape->SetMass(800);//Defaut : 800, Subaru : 1498
What do you think?
I don't know if my friction is enough or too much.
I don't know if my suspension is well tuned...
Thanx for your help.

Statistics: Posted by 686insomnia686 — Thu May 03, 2012 3:39 pm

]]> 2012-05-02T08:29:59+00:00 2012-05-02T08:29:59+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=27750#p27750 <![CDATA[Re: btRaycastVehicle Wheel rotation]]> YOU, the one of the 127 viewers who hasn't answer yet to my first post... :twisted:

When my wheel rotate too fast, there are a logical effect, the wheel look like rotate in the opposite direction...
I would like had any advise for counter this effect and keep a the good rotation direction.

I have try to decrease the rotation when it is too fast, but it's not a success "that's why I repost here...".

Thanx for your help and your particitation, don't be shy! :oops:

Statistics: Posted by 686insomnia686 — Wed May 02, 2012 8:29 am

]]> 2012-04-27T07:58:53+00:00 2012-04-27T07:58:53+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=27714#p27714 <![CDATA[Re: btRaycastVehicle Wheel rotation]]>
The basis is caculate with the Bullet Coordinate, so you have to change for your own coordinate.
My Coordinate System is :
+ Forward : X
+ Right : -y
+Up : Z

So my basis is :
btMatrix3x3 basis2(
fwd[0],-right[0],up[0],
fwd[1],-right[1],up[1],
fwd[2],-right[2],up[2]);

"If you have well define the setCoordinateSystem(), the m_wheelDirectionCS() and the m_wheelAxleCS().
It will be work fine..."

I'm little busy for now, but I gonna made a global correction for everyone, stay tune...

Statistics: Posted by 686insomnia686 — Fri Apr 27, 2012 7:58 am

]]> 2012-04-16T08:36:08+00:00 2012-04-16T08:36:08+00:00 https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=27658#p27658 <![CDATA[btRaycastVehicle Wheel rotation]]> As you can see, when I put a steering, my wheels turn but without steering, they don't.
This is my fonction where I modify the position and the rotation of each wheels :

Code: 

BOOLEAN PhysicsWorldBullet::DoProcessRayCastVehicle (RayCastVehicle* _rayCastVehicle){if (!GetSingleDelegate(_rayCastVehicle) || !_rayCastVehicle->m_vehicle ||  !_rayCastVehicle->m_vehicleRayCaster) return false;//Engine Force, Breaking Force and Vehicule Steering DefinitionfloatgEngineForce =  _rayCastVehicle->m_engineForce.GetValue();floatgBreakingForce = _rayCastVehicle->m_brake.GetValue();floatgVehicleSteering = -_rayCastVehicle->m_steering.GetValue();//Motor Wheels Definitionint wheelIndex = 0;if(gBreakingForce>0){((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->setBrake(gBreakingForce,wheelIndex);((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->applyEngineForce(0,wheelIndex);}else((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->applyEngineForce(gEngineForce,wheelIndex);wheelIndex = 1;if(gBreakingForce>0){((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->setBrake(gBreakingForce,wheelIndex);((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->applyEngineForce(0,wheelIndex);}else((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->applyEngineForce(gEngineForce,wheelIndex);//Steering Front WheelswheelIndex = 0;((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->setSteeringValue(gVehicleSteering,wheelIndex);wheelIndex = 1;((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->setSteeringValue(gVehicleSteering,wheelIndex);((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->getRigidBody()->activate();int i=0;float ajustementZ = 0.05;//put the 3D wheels upside the floorfor ( IteratorEx(it, _rayCastVehicle, Geometry3D); i<((btRaycastVehicle*)_rayCastVehicle->m_vehicle)->getNumWheels(); it++){it->Process(this);//Position((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->updateWheelTransform(i,true);btTransform newTransform = ((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->getWheelInfo(i).m_worldTransform;MATRIX Local = BtUtils3D::GetTransform(newTransform);//Get the Local matrix of the wheelit->SetWorldPosition(Local._41, Local._42, Local._43+ajustementZ);//Orientationfloat rotation = (float)((btRaycastVehicle*) _rayCastVehicle->m_vehicle)->getWheelInfo(i).m_rotation;//for the front wheelsif (i<2){if (gVehicleSteering<0)it->SetOrientation(NULL, -rotation, 0, gVehicleSteering + PI_2);elseit->SetOrientation(NULL, rotation, 0, gVehicleSteering + PI_2);}//for the back wheelselse{if (gVehicleSteering<0){if (gEngineForce<0)it->SetOrientation(NULL, -rotation, 0, PI_2);elseit->SetOrientation(NULL, rotation, 0, PI_2);}else{if (gEngineForce<0)it->SetOrientation(NULL, rotation, 0, PI_2);elseit->SetOrientation(NULL, -rotation, 0, PI_2);}}i++;}return true;}
For the parameter, I have tried a lot of solution and I never find a real good result:

Code: 

        m_engineForce.SetRange(-1000.0, 2000.0, 0.0);//(Min, Max, Init)m_brake.SetRange(0.0, 100.0, 0.0);//(Min, Max, Init)m_steering.SetRange(-0.3, 0.3, 0.0);//(Min, Max, Init)m_wheelDirectionCS.SetValues(0, 0, -1);m_wheelAxleCS.SetValues(0, -1, 0);m_wheelRadius = 0.31265;//Defaut : 0.5f, Subaru : 0.31265m_wheelWidth = 0.215f;//Defaut : 0.4f, Subaru : 0.215fm_wheelFriction = 10.5;//1000.0;//2.0;m_maxSuspensionTravelCm = 20.0f;//500.0;m_suspensionStiffness = 40.0f;//5.8f;//Defaut : 20.0, Subaru : 15.0m_suspensionDamping = 2.3f;//0.88;//2.3;m_suspensionCompression = 2.4;//0.83;//4.4;m_rollInfluence = 0.2f;m_suspensionRestLength = 0.1;m_connectionHeight = -0.4;//1.2;m_chassisLenght = 4.8;//Defaut : 2, Subaru : 4.8m_chassisWidth = 2; //Defaut : 1, Subaru : 2m_chassisHeight = 1.3;//Defaut : 0.5 , Subaru : 1.5m_SpeedKmH = 0;
The value of SpeedKmH changes it sign everytime, it's really boring, I have to put a condition like that :

Code: 

it->m_SpeedKmH = ((btRaycastVehicle*)it->m_vehicle)->getCurrentSpeedKmHour();if(it->m_SpeedKmH.GetValue() < 0) {        it->m_SpeedKmH*=-1;}
The value m_skidInfo stay always to "1.0", that is good! =)
In the video, we see that the color of the raycast change in blue when they are in contact with the ground.
The value m_rotation is increase by m_deltaRotation everytime (in btRaycastVehicle::updateVehicle( btScalar step )), but when there is no steering, m_deltaRotation is really small like "0.0000004" (in radian).

I hope you can help me because I'm totaly blocked for now.
Thank for your help,
Cordialy,
InSomNia.

Statistics: Posted by 686insomnia686 — Mon Apr 16, 2012 8:36 am

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