UCMC_JumpOff.cpp

void UCharacterMovementComponent::JumpOff(AActor* MovementBaseActor)
{
	if ( !bPerformingJumpOff )
	{
		bPerformingJumpOff = true;
		if ( CharacterOwner )
		{
			const float MaxSpeed = GetMaxSpeed() * 0.85f;
			Velocity += MaxSpeed * GetBestDirectionOffActor(MovementBaseActor);
			if ( Velocity.Size2D() > MaxSpeed )
			{
				Velocity = MaxSpeed * Velocity.GetSafeNormal();
			}

			if (HasCustomGravity())
			{
				FVector GravityRelativeVelocity = RotateWorldToGravity(Velocity);
				GravityRelativeVelocity.Z = JumpOffJumpZFactor * JumpZVelocity;
				Velocity = RotateGravityToWorld(GravityRelativeVelocity);
			}
			else
			{
				Velocity.Z = JumpOffJumpZFactor * JumpZVelocity;
			}
			
			SetMovementMode(MOVE_Falling);
		}
		bPerformingJumpOff = false;
	}
}

FVector UCharacterMovementComponent::GetBestDirectionOffActor(AActor* BaseActor) const
{
	// By default, just pick a random direction.  Derived character classes can choose to do more complex calculations,
	// such as finding the shortest distance to move in based on the BaseActor's Bounding Volume.
	const float RandAngle = FMath::DegreesToRadians(GetNetworkSafeRandomAngleDegrees());
	return FVector(FMath::Cos(RandAngle), FMath::Sin(RandAngle), 0.5f).GetSafeNormal();
}

float UCharacterMovementComponent::GetNetworkSafeRandomAngleDegrees() const
{
	float Angle = RandomStream.FRand() * 360.f;

	if (!IsNetMode(NM_Standalone))
	{
		// Networked game
		// Get a timestamp that is relatively close between client and server (within ping).
		FNetworkPredictionData_Server_Character const* ServerData = (HasPredictionData_Server() ? GetPredictionData_Server_Character() : NULL);
		FNetworkPredictionData_Client_Character const* ClientData = (HasPredictionData_Client() ? GetPredictionData_Client_Character() : NULL);

		float TimeStamp = Angle;
		if (ServerData)
		{
			TimeStamp = ServerData->CurrentClientTimeStamp;
		}
		else if (ClientData)
		{
			TimeStamp = ClientData->CurrentTimeStamp;
		}
		
		// Convert to degrees with a faster period.
		const float PeriodMult = 8.0f;
		Angle = TimeStamp * PeriodMult;
		Angle = FMath::Fmod(Angle, 360.f);
	}

	return Angle;
}