C++ FBodyInstance::IsInstanceAwake方法代码示例

bool UPrimitiveComponent::RigidBodyIsAwake(FName BoneName)
{
	FBodyInstance* BI = GetBodyInstance(BoneName);
	if(BI)
	{
		return BI->IsInstanceAwake();
	}

	return false;
}

bool UPrimitiveComponent::GetRigidBodyState(FRigidBodyState& OutState, FName BoneName)
{
	FBodyInstance* BI = GetBodyInstance(BoneName);
	if (BI && BI->IsInstanceSimulatingPhysics())
	{
		FTransform BodyTM = BI->GetUnrealWorldTransform();
		OutState.Position = BodyTM.GetTranslation();
		OutState.Quaternion = BodyTM.GetRotation();
		OutState.LinVel = BI->GetUnrealWorldVelocity();
		OutState.AngVel = BI->GetUnrealWorldAngularVelocity();
		OutState.Flags = (BI->IsInstanceAwake() ? ERigidBodyFlags::None : ERigidBodyFlags::Sleeping);
		return true;
	}

	return false;
}

bool UPrimitiveComponent::ApplyRigidBodyState(const FRigidBodyState& NewState, const FRigidBodyErrorCorrection& ErrorCorrection, FVector& OutDeltaPos, FName BoneName)
{
	bool bRestoredState = true;

	FBodyInstance* BI = GetBodyInstance(BoneName);
	if (BI && BI->IsInstanceSimulatingPhysics())
	{
		// failure cases
		const float QuatSizeSqr = NewState.Quaternion.SizeSquared();
		if (QuatSizeSqr < KINDA_SMALL_NUMBER)
		{
			UE_LOG(LogPhysics, Warning, TEXT("Invalid zero quaternion set for body. (%s:%s)"), *GetName(), *BoneName.ToString());
			return bRestoredState;
		}
		else if (FMath::Abs(QuatSizeSqr - 1.f) > KINDA_SMALL_NUMBER)
		{
			UE_LOG(LogPhysics, Warning, TEXT("Quaternion (%f %f %f %f) with non-unit magnitude detected. (%s:%s)"), 
				NewState.Quaternion.X, NewState.Quaternion.Y, NewState.Quaternion.Z, NewState.Quaternion.W, *GetName(), *BoneName.ToString() );
			return bRestoredState;
		}

		FRigidBodyState CurrentState;
		GetRigidBodyState(CurrentState, BoneName);

		const bool bShouldSleep = (NewState.Flags & ERigidBodyFlags::Sleeping) != 0;

		/////// POSITION CORRECTION ///////

		// Find out how much of a correction we are making
		const FVector DeltaPos = NewState.Position - CurrentState.Position;
		const float DeltaMagSq = DeltaPos.SizeSquared();
		const float BodyLinearSpeedSq = CurrentState.LinVel.SizeSquared();

		// Snap position by default (big correction, or we are moving too slowly)
		FVector UpdatedPos = NewState.Position;
		FVector FixLinVel = FVector::ZeroVector;

		// If its a small correction and velocity is above threshold, only make a partial correction, 
		// and calculate a velocity that would fix it over 'fixTime'.
		if (DeltaMagSq < ErrorCorrection.LinearDeltaThresholdSq  &&
			BodyLinearSpeedSq >= ErrorCorrection.BodySpeedThresholdSq)
		{
			UpdatedPos = FMath::Lerp(CurrentState.Position, NewState.Position, ErrorCorrection.LinearInterpAlpha);
			FixLinVel = (NewState.Position - UpdatedPos) * ErrorCorrection.LinearRecipFixTime;
		}

		// Get the linear correction
		OutDeltaPos = UpdatedPos - CurrentState.Position;

		/////// ORIENTATION CORRECTION ///////
		// Get quaternion that takes us from old to new
		const FQuat InvCurrentQuat = CurrentState.Quaternion.Inverse();
		const FQuat DeltaQuat = NewState.Quaternion * InvCurrentQuat;

		FVector DeltaAxis;
		float DeltaAng;	// radians
		DeltaQuat.ToAxisAndAngle(DeltaAxis, DeltaAng);
		DeltaAng = FMath::UnwindRadians(DeltaAng);

		// Snap rotation by default (big correction, or we are moving too slowly)
		FQuat UpdatedQuat = NewState.Quaternion;
		FVector FixAngVel = FVector::ZeroVector; // degrees per second
		
		// If the error is small, and we are moving, try to move smoothly to it
		if (FMath::Abs(DeltaAng) < ErrorCorrection.AngularDeltaThreshold )
		{
			UpdatedQuat = FMath::Lerp(CurrentState.Quaternion, NewState.Quaternion, ErrorCorrection.AngularInterpAlpha);
			FixAngVel = DeltaAxis.GetSafeNormal() * FMath::RadiansToDegrees(DeltaAng) * (1.f - ErrorCorrection.AngularInterpAlpha) * ErrorCorrection.AngularRecipFixTime;
		}

		/////// BODY UPDATE ///////
		BI->SetBodyTransform(FTransform(UpdatedQuat, UpdatedPos), true);
		BI->SetLinearVelocity(NewState.LinVel + FixLinVel, false);
		BI->SetAngularVelocity(NewState.AngVel + FixAngVel, false);

		// state is restored when no velocity corrections are required
		bRestoredState = (FixLinVel.SizeSquared() < KINDA_SMALL_NUMBER) && (FixAngVel.SizeSquared() < KINDA_SMALL_NUMBER);
	
		/////// SLEEP UPDATE ///////
		const bool bIsAwake = BI->IsInstanceAwake();
		if (bIsAwake && (bShouldSleep && bRestoredState))
		{
			BI->PutInstanceToSleep();
		}
		else if (!bIsAwake)
		{
			BI->WakeInstance();
		}
	}

	return bRestoredState;
}