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Trace Ignores rotation

Development Discussion C++ Gameplay Programming
#1

Hey so, im developing a sort of procedural Vaulting,Climbing system ( think of Mirrors Edge ) So far so good but i hit a issue with the tracing, here is a picture of the issue

My “Straight” traces to figure the mesh height work fine when i add the player rotation to them, the “Down” traces to figure if its long enough to be vaulteable Do not use the player rotation even tho
i add it on the code



void AProojectCharacter::TestTrace()
{
	FVector StartTrace;
	StartTrace = GetActorLocation();
	FVector EndTrace = StartTrace + Direction * 100; // and trace end is the camera location + an offset in the direction you are looking, the 200 is the distance at wich it checks
	FVector BestHitLocation;
	FVector WidthEndTrace;
	bool bVaultHeight = false;

// START STRAIGHT TRACES ///////////
	// Perform trace to retrieve hit info
	FCollisionQueryParams TraceParams(FName(TEXT("WeaponTrace")), true, this);
	TraceParams.bTraceAsyncScene = true;
	TraceParams.bReturnPhysicalMaterial = true;

	FHitResult Hit(ForceInit);
	if (GetWorld()->LineTraceSingle(Hit, StartTrace, EndTrace, ECC_WorldStatic, TraceParams))
	{

		// If we hit an object, start the scanning process
		for (int i = 1; i <= MaxVaultHeight; i++) // increase the Z a bit each trace so it goes up
		{
			StartTrace.Z = StartTrace.Z + VaultZIncrease;
			EndTrace.Z = EndTrace.Z + VaultZIncrease;


			if (GetWorld()->LineTraceSingle(Hit, StartTrace, EndTrace, ECC_WorldStatic, TraceParams))
			{
				// if we still hit the object after the max Height then its too high to vault
				DrawDebugLine(
					GetWorld(),
					StartTrace,
					Hit.Location,
					FColor(255, 0, 0),
					true,
					20,
					0,
					1
					);

			}

			else
			{
				// If we dont hit the object ( before the max increase ) then its not higher than us
				bVaultHeight = true; // height is vaulteable
				BestHitLocation = Hit.Location; // Grab the object height
				break;
			}

		}
/// END STRAIGHT TRACES ////////

//START "DOWN" TRACES /////////

		if (bVaultHeight) // "Down" Trace to figure if the object is long enough to vault over it
		{

			StartTrace = BestHitLocation;
			WidthEndTrace = StartTrace + GetActorLocation().Vector(); // Add the player rotation, here 
			StartTrace.Z = StartTrace.Z - UnitsToTraceDown; // 65
			

			for (int i = 1; i <= MaxVaultWidth; i++) 
			{
				StartTrace.X = StartTrace.X + VaultForwardIncrease;
				WidthEndTrace.X = WidthEndTrace.X + VaultForwardIncrease;
	

				if (!GetWorld()->LineTraceSingle(Hit, StartTrace, WidthEndTrace, ECC_WorldStatic, TraceParams))
				{
					SetActorLocation(WidthEndTrace);
					
				}

				DrawDebugLine(
					GetWorld(),
					StartTrace,
					WidthEndTrace,
					FColor(255, 0, 0),
					true,
					20,
					0,
					1
					);

			}

		}

	}
// End "down" traces /////////

}
#2

you are not showing any code for VaultForwardIncrease

but it should be some incremental amount in the direction the player is facing


const FVector VaultForwardIncrease = MyCharacter->GetActorRotation().Vector() * 25;

you could cache off the getting of the rotation as a vector outside of the loop


C++ Happy Happy

You can use += and *= etc to make the code a bit faster and easier to read

**this**


```

StartTrace.X = StartTrace.X + VaultForwardIncrease;
WidthEndTrace.X = WidthEndTrace.X + VaultForwardIncrease;

```



**becomes**


```

StartTrace.X    += VaultForwardIncrease;
WidthEndTrace.X += VaultForwardIncrease;

```





Rama
#3

Hey Rama

VaultForwardIncrease is just a float variable i change on the editor to control the space between the “Downward” traces , since i use it only to alter the StartTrace X and WidthEndTrace X
i cant use


VaultForwardIncrease = MyCharacter->GetActorRotation().Vector() * 25;

Since that gives me a vector and not a float

And thanks for the suggestion about using += & *=, it will for sure make things easier