C++ LevelHelper汽车设计旋转接头锚定问题

我试图复制这个链接的效果，我使用levelHelper来设计汽车。但无法复制这种效果。我想我在旋转关节上犯了错误。这是我正在尝试的代码

#include "GamePlayScene.h"
#include "LevelManager.h"
#include "Constants.h"
#include "iostream"





void GamePlayScene::InitPhysics()
{
    b2Vec2 gravity;
    gravity.Set(0.0f, -10.0f);
    m_pB2World = new b2World(gravity);
    m_pB2World->SetAllowSleeping(true);
    m_pB2World->SetContinuousPhysics(true);
    m_pDebugDraw = new GLESDebugDraw( LevelHelperLoader::pixelsToMeterRatio() );

    PTM_RATIO = LevelHelperLoader::pixelsToMeterRatio();
    m_pB2World->SetDebugDraw(m_pDebugDraw);


    m_pLoader= new LevelHelperLoader("track7.plhs");
    m_pLoader->addObjectsToWorld(m_pB2World,this);

    m_pB2World->ClearForces();

    //m_pB2World->DestroyJoint()

    LHSprite * carBody = m_pLoader->spriteWithUniqueName("CarBody");
    m_pCarBody = carBody->getBody();

    m_pCarBody->GetFixtureList()->SetDensity(CAR_BODY_DENSITY);
    m_pCarBody->ResetMassData();
    m_pCarBody->GetFixtureList()->SetFriction(CAR_BODY_FRICTION);
    m_pCarBody->GetFixtureList()->SetRestitution(CAR_BODY_RESTITUTION);

    LHSprite * chasis = m_pLoader->spriteWithUniqueName("Chasis");
    m_pChasis = chasis->getBody();

    m_pChasis->GetFixtureList()->SetDensity(CHASIS_DENSITY);
    m_pChasis->ResetMassData();
    m_pChasis->GetFixtureList()->SetFriction(CHASIS_FRICTION);
    m_pChasis->GetFixtureList()->SetRestitution(CHASIS_RESTITUTION);

    //m_pChasis->remove

    LHSprite * frontWheel = m_pLoader->spriteWithUniqueName("FrontWheel");
    m_pFrontWheel = frontWheel->getBody();

    m_pFrontWheel->GetFixtureList()->SetDensity(FRONT_WHEEL_DENSITY);
    m_pFrontWheel->ResetMassData();
    m_pFrontWheel->GetFixtureList()->SetFriction(FRONT_WHEEL_FRICTION);
    m_pFrontWheel->GetFixtureList()->SetRestitution(FRONT_WHEEL_RESTITUTION);

    LHSprite * rearWheel = m_pLoader->spriteWithUniqueName("RearWheel");
    m_pRearWheel = rearWheel->getBody();

    m_pRearWheel->GetFixtureList()->SetDensity(REAR_WHEEL_DENSITY);
    m_pRearWheel->ResetMassData();
    m_pRearWheel->GetFixtureList()->SetFriction(REAR_WHEEL_FRICTION);
    m_pRearWheel->GetFixtureList()->SetRestitution(REAR_WHEEL_RESTITUTION);

    LHSprite * frontDamper = m_pLoader->spriteWithUniqueName("FrontDamper");
    m_pFrontDamper = frontDamper->getBody();

    m_pFrontDamper->GetFixtureList()->SetDensity(FRONT_DAMPER_DENSITY);
    m_pFrontDamper->ResetMassData();
    m_pFrontDamper->GetFixtureList()->SetFriction(FRONT_DAMPER_FRICTION);
    m_pFrontDamper->GetFixtureList()->SetRestitution(FRONT_DAMPER_RESTITUTION);

    LHSprite * rearDamper = m_pLoader->spriteWithUniqueName("RearDamper");
    m_pRearDamper = rearDamper->getBody();

    m_pRearDamper->GetFixtureList()->SetDensity(REAR_DAMPER_DENSITY);
    m_pRearDamper->ResetMassData();
    m_pRearDamper->GetFixtureList()->SetFriction(REAR_DAMPER_FRICTION);
    m_pRearDamper->GetFixtureList()->SetRestitution(REAR_DAMPER_RESTITUTION);

    b2PolygonShape * shape = (b2PolygonShape *)m_pChasis->GetFixtureList()->GetShape();

    //shape->SetAsBox(

    LHJoint * frontPrismJoint = frontDamper->jointWithUniqueName("FrontDamperChasis");
    LH_JOINT_TYPE type2 = frontPrismJoint->getType();

    if(type2 == LH_PRISMATIC_JOINT)
    {
        //m_pFrontPrismJoint = (b2PrismaticJoint *)frontPrismJoint;
        //b2PrismaticJointDef prismJointDef;

        frontPrismJointDef = new b2PrismaticJointDef();

        //b2Vec2 anchor = m_pFrontDamper->GetWorldCenter() - m_pChasis->GetWorldCenter();

        frontPrismJointDef->Initialize(m_pChasis,m_pFrontDamper, m_pFrontDamper->GetWorldCenter(), b2Vec2(0, 1));

        frontPrismJointDef->enableLimit = FRONT_PRISM_JOINT_ENABLE_LIMIT;
        frontPrismJointDef->enableMotor = FRONT_PRISM_JOINT_ENABLE_MOTOR;
        frontPrismJointDef->lowerTranslation = FRONT_PRISM_JOINT_LOWERTRANSLATION;
        frontPrismJointDef->upperTranslation = FRONT_PRISM_JOINT_UPPERTRANSLATION;
        frontPrismJointDef->maxMotorForce = FRONT_PRISM_JOINT_MAXMOTORFORCE;

        //b2Joint * joint = (b2Joint *)frontPrismJoint;
        //frontPrismJointDef->

        m_pFrontSpring = (b2PrismaticJoint *)m_pB2World->CreateJoint(frontPrismJointDef);

        //m_pB2World->DestroyJoint(joint);
    }

    LHJoint * rearPrismJoint = rearDamper->jointWithUniqueName("RearDamperChasis");
    type2 = rearPrismJoint->getType();

    if(type2 == LH_PRISMATIC_JOINT)
    {
        //m_pRearPrismJoint = (b2PrismaticJoint *)rearPrismJoint;

        rearPrismJointDef = new b2PrismaticJointDef();

        rearPrismJointDef->Initialize(m_pChasis, m_pRearDamper, m_pRearDamper->GetWorldCenter(), b2Vec2(0, 1));

        rearPrismJointDef->enableLimit = REAR_PRISM_JOINT_ENABLE_LIMIT;
        rearPrismJointDef->enableMotor = REAR_PRISM_JOINT_ENABLE_MOTOR;
        rearPrismJointDef->lowerTranslation = REAR_PRISM_JOINT_LOWERTRANSLATION;
        rearPrismJointDef->upperTranslation = REAR_PRISM_JOINT_UPPERTRANSLATION;
        rearPrismJointDef->maxMotorForce = REAR_PRISM_JOINT_MAXMOTORFORCE;

        m_pRearSpring = (b2PrismaticJoint *)m_pB2World->CreateJoint(rearPrismJointDef);
    }

    LHJoint * frontRevoluteJoint = frontWheel->jointWithUniqueName("FrontDamperWheel");
    //frontWheel->jo
    LH_JOINT_TYPE type = frontRevoluteJoint->getType();

    if(type == LH_REVOLUTE_JOINT)
    {
        m_pFrontMotor = (b2RevoluteJoint *)frontRevoluteJoint;

        frontRevoluteJointDef = new b2RevoluteJointDef();

        frontRevoluteJointDef->Initialize(m_pFrontDamper, m_pFrontWheel, m_pFrontWheel->GetWorldCenter());

        frontRevoluteJointDef->motorSpeed = FRONT_REVOLUTE_JOINT_MOTORSPEED;
        frontRevoluteJointDef->maxMotorTorque = FRONT_REVOLUTE_JOINT_MAXMOTORTORQUE;
        frontRevoluteJointDef->enableMotor = FRONT_REVOLUTE_JOINT_ENABLE_MOTOR;
        m_fFrontMotorSpeed = FRONT_REVOLUTE_JOINT_MOTORSPEED;
        m_fFrontMaxMotorTorque = FRONT_REVOLUTE_JOINT_MAXMOTORTORQUE;
        m_pFrontMotor = (b2RevoluteJoint *)m_pB2World->CreateJoint(frontRevoluteJointDef);
    }

    LHJoint * rearRevoluteJoint = rearWheel->jointWithUniqueName("RearDamperWheel");
    type = rearRevoluteJoint->getType();

    if(type == LH_REVOLUTE_JOINT)
    {
        //m_pRearRevoluteJoint = (b2RevoluteJoint *)rearRevoluteJoint;

        rearRevoluteJointDef = new b2RevoluteJointDef();

        rearRevoluteJointDef->Initialize(m_pRearDamper, m_pRearWheel, m_pRearWheel->GetWorldCenter());// - b2Vec2(0.1f,0.0f));

        rearRevoluteJointDef->motorSpeed = REAR_REVOLUTE_JOINT_MOTORSPEED;
        rearRevoluteJointDef->maxMotorTorque = REAR_REVOLUTE_JOINT_MAXMOTORTORQUE;
        rearRevoluteJointDef->enableMotor = REAR_REVOLUTE_JOINT_ENABLE_MOTOR;
        m_fRearMotorSpeed = REAR_REVOLUTE_JOINT_MOTORSPEED;
        m_fRearMaxMotorTorque = REAR_REVOLUTE_JOINT_MAXMOTORTORQUE;
        //revoluteJointDef. 
        m_pRearMotor = (b2RevoluteJoint *)m_pB2World->CreateJoint(rearRevoluteJointDef);

        //m_fMotorSpeed = m_pRearMotor->GetMotorSpeed();
    }


}

void GamePlayScene::ccTouchesBegan(cocos2d::CCSet *pTouches, CCEvent *pEvent) 
{

    CCTouch * touch = (CCTouch *)(pTouches->anyObject());
    CCPoint location = touch->getLocationInView();
    location = CCDirector::sharedDirector()->convertToGL(location);

    if(location.x > mSize.width/2)
    {
        bIsAcceleration = true;
        bIsBrake = false;

        m_pFrontMotor->EnableMotor(true);
        m_pRearMotor->EnableMotor(true);

        //m_pFrontWheel->SetLinearVelocity(b2Vec2(-20.0f, 0.0f));

        direction = 1;
        oppositeDirection = -1;
    }
    else
    {
        m_pFrontMotor->EnableMotor(true);
        m_pRearMotor->EnableMotor(true);
        bIsAcceleration = false;
        bIsBrake = true;
        direction = -1;
        oppositeDirection = 1;

        //m_pRearWheel->SetLinearVelocity(b2Vec2(25.0f, 0.0f));
    }

}
void GamePlayScene::ccTouchesMoved(CCSet *pTouches, CCEvent *pEvent)
{
    //bIsAcceleration=true;
}

void GamePlayScene::ccTouchesEnded(CCSet *pTouches, CCEvent *pEvent)
{
    bIsAcceleration=false;
    bIsBrake = false;

    //direction *= -1;
    //m_pFrontMotor->EnableMotor(false);
}

void GamePlayScene::clickOnBackwardButn(CCObject * pSender)
{
    bIsAcceleration = false;
    m_pFrontMotor->EnableMotor(false);
    m_pRearMotor->EnableMotor(false);

    //m_fMotorSpeed = 0.0;
    m_pRearMotor->SetMotorSpeed(-50.0f);
    m_pFrontMotor->SetMotorSpeed(-50.0f);

    m_pRearMotor->SetMaxMotorTorque(50.0f);
    m_pFrontMotor->SetMaxMotorTorque(50.0f);
    //m_pRearWheel->SetLinearVelocity(b2Vec2(-(10.0f),0.0f));
}

void GamePlayScene::clickOnForwardButn(CCObject * pSender)
{
    m_pFrontMotor->EnableMotor(true);
    m_pRearMotor->EnableMotor(true);
    bIsAcceleration = true;

    //m_pFrontWheel->SetLinearVelocity(b2Vec2(15.0f + m_fVelocityAcceleration,0.0f));
}

void GamePlayScene::draw()
{
    CCLayer::draw();
    ccGLEnableVertexAttribs( kCCVertexAttribFlag_Position );

    kmGLPushMatrix();

    m_pB2World->DrawDebugData();
    kmGLPopMatrix();

}

void GamePlayScene::update(float dt)
{


    b2Vec2 position=m_pFrontWheel->GetPosition();
    int x=position.x*32.0f;
    int y=position.y*32.0f;
    this->setPositionX(480.0f*90/100 + -x);


    if(bIsAcceleration)
    {


        m_pFrontMotor->SetMotorSpeed(30 * M_PI * direction);
        m_pFrontMotor->SetMaxMotorTorque(34);
        m_pRearMotor->SetMotorSpeed(30 * M_PI * direction);
        m_pRearMotor->SetMaxMotorTorque(24);



        //m_pChasis->ApplyTorque(20 * direction);
    }
    else if(bIsBrake)
    {



          m_pFrontMotor->SetMotorSpeed(30 * M_PI * direction);
          m_pFrontMotor->SetMaxMotorTorque(24);
          m_pRearMotor->SetMotorSpeed(30 * M_PI * direction);
          m_pRearMotor->SetMaxMotorTorque(34);

          //m_pCarBody->ApplyTorque(30 * direction);

    }
    else
    {

          m_pFrontMotor->SetMotorSpeed(0.0f);
          m_pFrontMotor->SetMaxMotorTorque(0.5f);
          m_pRearMotor->SetMotorSpeed(0.0f);
          m_pRearMotor->SetMaxMotorTorque(0.5f);
    }

    /*if(m_fMotorSpeed >= 50.0f)
    {
        m_fMotorSpeed = 50.0f;
    }*/



    m_pFrontSpring->SetMaxMotorForce(10 + abs(100 * pow(m_pFrontSpring->GetJointTranslation(), 2)));
    m_pFrontSpring->SetMotorSpeed(-4*pow(m_pFrontSpring->GetJointTranslation(), 1));

    m_pRearSpring->SetMaxMotorForce(30 + abs(100 * pow(m_pRearSpring->GetJointTranslation(), 2)));
    m_pRearSpring->SetMotorSpeed((m_pRearSpring->GetMotorSpeed() - 10*m_pRearSpring->GetJointTranslation())*0.4);

    int32 velocityIterations = 8;
    int32 positionIterations = 6;
    m_pB2World->Step(dt, velocityIterations, positionIterations);

}

void GamePlayScene::menuCloseCallback(CCObject* pSender)
{
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT) || (CC_TARGET_PLATFORM == CC_PLATFORM_WP8)
    CCMessageBox("You pressed the close button. Windows Store Apps do not implement a close button.","Alert");
#else
    CCDirector::sharedDirector()->end();
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
    exit(0);
#endif
#endif
}

---

太多的代码无法查看。你也没有解释问题所在。你期望发生什么事？？发生了什么？我试图遵循链接代码，但无法对棱柱关节产生相同的效果&为什么我们需要将棱柱关节锚定点设置在底盘质心上。为什么要使用cos和sin值。