GAS/Motion Matching - controlling rotation through code?

Development Programming & Scripting
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1

I’ve looked into GAS and motion matching, and I need code that will rotate the character, when the player has no control on it. He should however still have control of the camera.

I tried many settings, but I can’t seem to get it.
The character seems to always follow the control rotation, which seems to match the camera rotation.

I hope someone here knows how to accomplish this :pray:

2

Looking for the same, a quick look into the class UCharacterTrajectoryComponent take me to this:

void FCharacterTrajectoryData::UpdateDataFromCharacter(float DeltaSeconds, const ACharacter* Character)
{
if (!ensure(Character))
{
return;
}

// An AnimInstance might call this during an AnimBP recompile with 0 delta time.
if (DeltaSeconds <= 0.f)
{
   return;
}

if (const UCharacterMovementComponent\* MoveComp = Character->GetCharacterMovement())
{
   MaxSpeed = FMath::Max(MoveComp->GetMaxSpeed() \* MoveComp->GetAnalogInputModifier(), MoveComp->GetMinAnalogSpeed());
   BrakingDeceleration = FMath::Max(0.f, MoveComp->GetMaxBrakingDeceleration());
   bOrientRotationToMovement = MoveComp->bOrientRotationToMovement;

   Velocity = MoveComp->Velocity;
   Acceleration = MoveComp->GetCurrentAcceleration();

   if (Acceleration.IsZero())
   {
      Friction = MoveComp->bUseSeparateBrakingFriction ? MoveComp->BrakingFriction : MoveComp->GroundFriction;
      const float FrictionFactor = FMath::Max(0.f, MoveComp->BrakingFrictionFactor);
      Friction = FMath::Max(0.f, Friction \* FrictionFactor);
   }
   else
   {
      Friction = MoveComp->GroundFriction;
   }
}
else
{
   ensure(false);
}

// @todo: Simulated proxies don't have controllers, so they'll need some other mechanism to account for controller rotation rate.
const AController\* Controller = Character->GetController();
if (Controller)
{
   float DesiredControllerYaw = Controller->GetDesiredRotation().Yaw;
   
   const float DesiredYawDelta = DesiredControllerYaw - DesiredControllerYawLastUpdate;
   DesiredControllerYawLastUpdate = DesiredControllerYaw;

   ControllerYawRate = FRotator::NormalizeAxis(DesiredYawDelta) \* (1.f / DeltaSeconds);
   ControllerYawRateClamped = ControllerYawRate;
   if (MaxControllerYawRate >= 0.f)
   {
      ControllerYawRateClamped = FMath::Sign(ControllerYawRate) \* FMath::Min(FMath::Abs(ControllerYawRate), MaxControllerYawRate);
   }
}

if (const USkeletalMeshComponent\* MeshComp = Character->GetMesh())
{
   Position = MeshComp->GetComponentLocation();
   Facing = MeshComp->GetComponentRotation().Quaternion();
   MeshCompRelativeRotation = MeshComp->GetRelativeRotation().Quaternion();
}
else
{
   ensure(false);
}

}

Where as you can se the ControllerYawRate only obeys the Control rotation, same with the Search pose node, you need to go c++ in order to fix this AFAIK