Player Rotation Left, RIght, Forward, Backwards

Development Programming & Scripting C++
1

Hello I was hoping someone will help me with a math problem.
Doing traces from a melee weapon I need to figure out what side the player was struck from.
To determine what hit animation to play, I realize it may be trivial to some but am stuck. :stuck_out_tongue:

I get the the following data from the HitResult for the trace.


HitResult.ImpactPoint; // Location
Location.Rotation(); // Roation

// Get Direction and Distance
FVector Direction(ForceInitToZero);
float Distance = 0.f;
Location.ToDirectionAndLength(Direction, Distance);

I can get the same data for the player but am unsure what to do.
Google seems little help at this point.

Thanks for any help!

Cheers!

2

You could get the TraceStart from your trace, get the look at direction, and compare the angle of that against the rotation of the actor you’re hitting?

3

You could try and get the angle between the impact point and the actors forward vector. That could give you where the player was hit.
I did this once for line trace (just a note that my actors were always on xy plane, they only rotated around the z axis) and this worked for me.


FVector c = FVector::CrossProduct(HitResult.ImpactPoint - HitResult.Actor->GetActorLocation(), HitResult.Actor->GetActorForwardVector());
4

Thank you guys i will give it a try and report back.
Cheers!

Edit: Ok so this is the solution i came up with in the end.
Thank you for stearing me in the right direction.


// Get the local location for where player was hit.
const FVector HitActorLocation = HitResult.GetActor()->GetActorLocation();
const FRotator HitActorRotation = HitResult.GetActor()->GetActorRotation();
FVector LocalSpaceHitLocation = HitActorRotation.UnrotateVector(HitResult.ImpactPoint - HitActorLocation);

// Normalize Result
/* X >= 0.0 == Forward, X < 0.0 == Backward */
/* Y >= 0.0 == Right, Y < 0.0 == Left */
LocalSpaceHitLocation.Normalize();