C++ UPrimitiveComponent::AddTorque方法代码示例

void UVaOceanBuoyancyComponent::PerformWaveReaction(float DeltaTime)
{
	AActor* MyOwner = GetOwner();

	if (!UpdatedComponent || MyOwner == NULL)
	{
		return;
	}
	UPrimitiveComponent* OldPrimitive = Cast<UPrimitiveComponent>(UpdatedComponent);

	const FVector OldLocation = MyOwner->GetActorLocation();
	const FRotator OldRotation = MyOwner->GetActorRotation();
	const FVector OldLinearVelocity = OldPrimitive->GetPhysicsLinearVelocity();
	const FVector OldAngularVelocity = OldPrimitive->GetPhysicsAngularVelocity();
	const FVector OldCenterOfMassWorld = OldLocation + OldRotation.RotateVector(COMOffset);
	const FVector OwnerScale = MyOwner->GetActorScale();

	// XYZ === Throttle, Steering, Rise == Forwards, Sidewards, Upwards
	FVector X, Y, Z;
	GetAxes(OldRotation, X, Y, Z);

	// Process tension dots and get torque from wind/waves
	for (FVector TensionDot : TensionDots)
	{
		// Translate point to world coordinates
		FVector TensionDotDisplaced = OldRotation.RotateVector(TensionDot + COMOffset);
		FVector TensionDotWorld = OldLocation + TensionDotDisplaced;

		// Get point depth
		float DotAltitude = GetAltitude(TensionDotWorld);

		// Don't process dots above water
		if (DotAltitude > 0)
		{
			continue;
		}
		
		// Surface normal (not modified!)
		FVector DotSurfaceNormal = GetSurfaceNormal(TensionDotWorld) * GetSurfaceWavesNum();
		// Modify normal with real Z value and normalize it
		DotSurfaceNormal.Z = GetOceanLevel(TensionDotWorld);
		DotSurfaceNormal.Normalize();

		// Point dynamic pressure [http://en.wikipedia.org/wiki/Dynamic_pressure]
		// rho = 1.03f for ocean water
		FVector WaveVelocity = GetWaveVelocity(TensionDotWorld);
		float DotQ = 0.515f * FMath::Square(WaveVelocity.Size());
		FVector WaveForce = FVector(0.0,0.0,1.0) * DotQ /* DotSurfaceNormal*/ * (-DotAltitude) * TensionDepthFactor;
		
		// We don't want Z to be affected by DotQ
		WaveForce.Z /= DotQ;

		// Scale to DeltaTime to break FPS addiction
		WaveForce *= DeltaTime;

		// Apply actor scale
		WaveForce *= OwnerScale.X;// *OwnerScale.Y * OwnerScale.Z;

		OldPrimitive->AddForceAtLocation(WaveForce * Mass, TensionDotWorld);
	}

	// Static metacentric forces (can be useful on small waves)
	if (bUseMetacentricForces)
	{
		FVector TensionTorqueResult = FVector(0.0f, 0.0f, 0.0f);

		// Calc recovering torque (transverce)
		FRotator RollRot = FRotator(0.0f, 0.0f, 0.0f);
		RollRot.Roll = OldRotation.Roll;
		FVector MetacenterDisplaced = RollRot.RotateVector(TransverseMetacenter + COMOffset);
		TensionTorqueResult += X * FVector::DotProduct((TransverseMetacenter - MetacenterDisplaced), 
			FVector(0.0f, -1.0f, 0.0f)) * TensionTorqueRollFactor;

		// Calc recovering torque (longitude)
		FRotator PitchRot = FRotator(0.0f, 0.0f, 0.0f);
		PitchRot.Pitch = OldRotation.Pitch;
		MetacenterDisplaced = PitchRot.RotateVector(LongitudinalMetacenter + COMOffset);
		TensionTorqueResult += Y * FVector::DotProduct((LongitudinalMetacenter - MetacenterDisplaced), 
			FVector(1.0f, 0.0f, 0.0f)) * TensionTorquePitchFactor;

		// Apply torque
		TensionTorqueResult *= DeltaTime;
		TensionTorqueResult *= OwnerScale.X;// *OwnerScale.Y * OwnerScale.Z;
		OldPrimitive->AddTorque(TensionTorqueResult);
	}
}