//움직이는 월드의 속도를 캐릭터에 반영한다.

    hkpSurfaceInfo surfaceInfo;

    {

        hkArray<hkpCharacterRigidBody::SupportInfo> supportInfo;

 

        hkStepInfo stepInfo;

        stepInfo.m_deltaTime = fTimestep;

        stepInfo.m_invDeltaTime = 1.0f / fTimestep;

        stepInfo.m_endTime = TIME_STEP;

        surfaceInfo.m_supportedState = m_pHavokRigidBody->getSupportInfo( stepInfo, supportInfo );

        if ( surfaceInfo.m_supportedState != hkpSurfaceInfo::UNSUPPORTED )

            GetGround( m_pHavokRigidBody, supportInfo, surfaceInfo );

    }

    //움직이는 월드의 속도를 더한다.

    output.m_velocity.add4( surfaceInfo.m_surfaceVelocity );

//하복 데모의 MovingSupportRbDemo.cpp getGround( ) 참고

void HavokCharacter::GetGround( hkpCharacterRigidBody* characterRigidBody, const hkArray<hkpCharacterRigidBody::SupportInfo>& supportInfo, hkpSurfaceInfo& ground ) const

{

    float fTimestep = 1.0f / 60.0f;

    // Produce an average version of the ground

 

    ground.m_surfaceVelocity.setZero4();

    ground.m_surfaceNormal.setZero4();

    ground.m_surfaceDistanceExcess = 0.0f;

    ground.m_surfaceIsDynamic = false;

 

    const int numSupportInfo = supportInfo.getSize();

    for ( int i = 0; i < numSupportInfo; ++i )

    {

        const hkpCharacterRigidBody::SupportInfo& support = supportInfo[i];

        ground.m_surfaceNormal.add4( support.m_point.getNormal() );

        ground.m_surfaceDistanceExcess += support.m_point.getDistance();

        const hkpMotion::MotionType motionType = support.m_rigidBody->getMotionType();

        if ( motionType == hkpMotion::MOTION_KEYFRAMED )

        {

            hkVector4 pointVelocity;

            support.m_rigidBody->getPointVelocity( support.m_point.getPosition(), pointVelocity );

            ground.m_surfaceVelocity.add4( pointVelocity );

        }

        /*

        else if ( motionType != hkpMotion::MOTION_FIXED )

        {

            ground.m_surfaceIsDynamic = true;

            if ( m_bodyType.getWithDefault ( support.m_rigidBody, false ) == hkBool32( true ) )

            {

                hkVector4 pointVelocity;

                support.m_rigidBody->getPointVelocity( support.m_point.getPosition(), pointVelocity );

                ground.m_surfaceVelocity.add4( pointVelocity );

            }

        }

        */

    }

 

    ground.m_surfaceNormal.normalize3();

    const hkReal portion = 1.f / numSupportInfo;

 

    ground.m_surfaceVelocity.mul4( portion );

    ground.m_surfaceDistanceExcess = ( ground.m_surfaceDistanceExcess * portion );

 

    if ( ground.m_surfaceIsDynamic )

    {

        // We need to apply the character's weight onto dynamic bodies. We do this by

        // setting a positive surfaceDistanceExcess which the controller should try

        // to reduce by applying gravity.

        ground.m_surfaceDistanceExcess = 0.01f;

    }

    else

    {

        // For fixed and keyframed bodies, we subtract m_hardSupportDistance from the excess

        // to ensure an extra gap below the character. This improves the smoothness of the

        // character's motion over the ground.

        ground.m_surfaceDistanceExcess -= characterRigidBody->m_hardSupportDistance;

    }

 

    // For dynamic supporting bodies which do keep velocity, we apply gravity representing the

    // force required to keep the character in position.

    hkVector4 impulse;

    {

        hkpWorld* pWorld = HavokManager::Instance()->GetWorld();

        impulse.setMul4( characterRigidBody->m_character->getMass() * fTimestep, pWorld->getGravity() );

        // We want the component of the impulse tangential to the surface.

        const hkSimdReal normal = impulse.dot3( ground.m_surfaceNormal );

        impulse.setAddMul4( impulse, ground.m_surfaceNormal, -normal );

        // Divide the amount of impulse by the number of supporting surfaces

        impulse.mul4( 1.0f / numSupportInfo );

    }

 

    /*

    for ( int i = 0; i < numSupportInfo; ++i )

    {

        const hkpCharacterRigidBody::SupportInfo& support = supportInfo[i];

 

        if ( m_bodyType.getWithDefault( support.m_rigidBody, false ) == hkBool32( true ) )

        {

            // Apply the impulse at the contact point.

            support.m_rigidBody->applyPointImpulse( impulse, support.m_point.getPosition() );

        }

    }

    */

}