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Detect Surface Angle

Official Documentation:


Detect the Surface: get important data for example the angle to decide if it's climable or not.


Useful to detect if a Wall would be steep enough to be Climbable.

Line Trace

First we need something to detect the Mesh/Object, so we'll use a LineTrace for that.


// In this example we'll implement the LineTrace inside the Tick
// but you can move the Code wherever you want.
void AYourCharacter::Tick(float Deltatime)

// Define the parameters for the LineTrace
FHitResult Hit; // Stores the Hit-Result from the first blocking hit
// Getting the Forward Vector, where the Actor is currently facing
// and multipling it by 1000 units along the axis to define the End Point
FVector Forward = GetActorLocation()->GetForwardVector() * 1000.f;
// Get the Actors Location which will be our Starting point for the Trace
FVector Start = GetActorLocation();
FVector End = Start + Forward; // Combine both to have the full LineTrace
FCollisionQueryParams CollisionParams; // define the collision
CollisionParams.AddIgnoredActor(this); // add Actors to ignore, in this case this Actor
// if you want to ignore more Actors, just add the Line above again
// and add a different Actor Type inside the parantheses e.g: AddIgnoredActor(SomeActor::StaticClass())

if (Controller != nullptr) //check if the Controller is not null
// Call the LineTrace Function and provide the parameters we just defined
GetWorld()->LineTraceSingleByChannel(Hit, Start, End, ECC_Visibility, CollisionParams);
// To vizualize the LineTrace in-game, lets also draw a DebugLine:
DrawDebugLine(GetWorld(), Start, End, Hit.bBlockingHit ? FColor::Blue : FColor::Red, false, 5.0f, 1.0f, 10.0f);

// Check if ImpactNormal and your Characters GetActorUpVector() are not null
if (Hit.ImpactNormal && GetActorUpVector())
float DotProduct = FVector::DotProduct(Hit.ImpactNormal, GetActorUpVector());

if (FMath::Abs(DotProduct) < ClimbableAngleThreshold)
// Wall is climbable.
// if DotProduct is above 0, then its angled and if its 1 then the surface is vertical
// if nothing got hit, you can do something here
// or just Log that nothing got got
UE_LOG(LogTemp, Log, TEXT("Nothing got got"));

This was an example on how to detect surface angles with normals in Unreal Engine C++.