Turn In Place Almost Perfect

Development Programming & Scripting
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1

Need help fixing a small bug, when turning (say right first however many times), the turn in place works, but when i turn left the second time after turning right first the left turn is messed up (root yaw offset is being set and sign is flipping incorrectly). vice versa if i turn left first then right the second time, left works great and right turn is messed up.

TurnInPlaceAlmostPerfect
TurnInPlaceAlmostPerfect1279×1203 128 KB

2

I feel like this is a job for quaternions. You won’t have the sign issue with them.

3

The sign flip is more random than i thought after testing and debugging. Could you type some example of a UE quaternion FQuat, I’m not sure how to start?

4

This might work. Haven’t tested it though:

#include "Math/Quat.h"

void AYourCharacter::RotateInPlaceWithQuaternion(float DeltaTime)
{    
    if (FMath::IsNearlyZero(GetCharacterMovement()->Velocity.SizeSquared()))
    {        
        FQuat CurrentRotation = GetActorQuat();

        // Create a quaternion for the desired rotation (ie. rotating around the Z-axis)
        FQuat DesiredRotation = FQuat(FRotator(0.0f, RotationSpeed * DeltaTime, 0.0f));
       
        FQuat NewRotation = DesiredRotation * CurrentRotation;        
        SetActorRotation(NewRotation);
    }
}
5

Thanks, I’ll see what i can come up with.

6

So I’m using rotate root bone to keep my feet forward until yaw offset is 90 ,then using yawoffsetABS to keep from passing 180 -180 which eliminates sign flip. I tried FRotators, no change. Now trying quaternions, just not sure how to properly normalize or get a Yaw from it, or delta.