Where can I find WorldToComponent ?

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1

I’m looking to transform the world z up vectors to my characters local capsule component Up Vector. I was told there is a method in the capsule component - but I only find Component to World.

Thanks!

2

I’ve looked all over the UE4’s stuff and I can’t find a world to component method. So I’m trying to assemble one and I’m curious about the functionality of UnRotateVector.

FVector UCharacterMovementComponent::hkvWorldToComponent(FVector VectorToRotate)
{
FRotator compToWorldTrans = CharacterOwner->CapsuleComponent->GetComponentToWorld().Rotator();
FVector rotatedVector = compToWorldTrans.UnrotateVector(VectorToRotate);
return rotatedVector;
}

3

The above code seems to produce the character spiraling towards the center (0,0,0). I was tested it on the DoJump, by Calling hkvWorldToComponent(0,0,GetGravityZ()).Z I was trying to convert the GetGravity.Z to Component space of the character capsule.

4

It’s simply the inverse of ComponentToWorld, so to transform a world direction vector into a local vector in a component’s space:

FTransform T = TheComponent->GetComponentTransform();
FVector LocalVector = T.InverseTransformVectorNoScale(WorldVector);
5

Okay so I’m having difficulty getting this to work. I think I’m missing something important. Here’s the code: (Also I don’t know how to paste code to make it look nice so sorry)

//World to Component Method
FVector UCharacterMovementComponent::hkvWorldToComponent(FVector VectorToRotate)
{	
FTransform compToWorldTrans = CharacterOwner->CapsuleComponent->ComponentToWorld;
	FVector rotatedVector = compToWorldTrans.InverseTransformVectorNoScale(VectorToRotate);
	return rotatedVector;
}

/*Do Jump, Here I'm not using the method(Though I would like to) this works in getting the jump to be along the character capsule's upvector. */

    Velocity += CharacterOwner->GetActorUpVector() * JumpZVelocity;

/*PhysFalling section,  changing this line to use the character capsule's up vector will work but I think it would be best to just rotate the vector so I can always use the Z is up logic */

    Velocity = NewFallVelocity(Velocity, hkvWorldToComponent(FVector(0.f, 0.f, GetGravityZ())), timeTick);

When I runt game, the character will jump up along capsules UpVector so that approach works, but once when the game starts the character falls from a height (so I can check that he’s falling along his UpVector) Using the inverse rotated Vector the character falls along the World “Z”. This is what I’m trying to avoid.

6

I’m still having trouble getting the correct vector. When I use CharacterOwner->GetActorUpVector() I get the correct vector that I’m looking for. What I’m trying to do is rotate the GetGravity to this so that I can still use the up logic throughout the character Movement Component. I was told that I could create a WorldToComponent function to rotate the vector to my characters so I could still reference the Z Axis when evaluating.

Currently the way I’m trying to rotate the FVector( 0,0,GetGravityZ) is producing the vector along which the character falls to be a bit more random.