Scaling objects based on hand distance

[Vulkanos]

Hey everyone,

I want to scale objects based on the distance between pinched handL & handR.
But I want the ability to keep on scaling the object bigger / smaller when I pinch both hands again.

Similar to the DetectionExamples - PinchMovementDemo which is using the LeapRTS script.

My object currently scales correctly, but every time I pinch my fingers to scale it even bigger, it just pops back and gets small again. I did this with this little piece of code:

selectedObject.transform.localScale = Vector3.one * Vector3.Distance (_pinchDetectorA.Position, _pinchDetectorB.Position) ;

I worked out what to do in theory, but I can't really get it to work.
I would have to store the distance between the first pinched hands.
And then if the distance gets bigger the object has to get bigger and vice versa.
But how would I do that?

In addition to that, I would like to move objects threw my room just by pinching in the air.
I don't want the objects to teleport to my hand position, but rather move them based on my hand movement. Currently the objects move, but teleport to my hand (I know why) but I have no clue how to fix it.

Current code for moving objects:

Vector3 objVectorPos = selectedObject.transform.position;
objVectorPos.x = singlePinch.transform.position.x;
objVectorPos.z = singlePinch.transform.position.z;
selectedObject.transform.position = objVectorPos;

In case someone wants to view the whole script Ill summarize what it does and upload it as well for clarity.
I can choose from multiple objects by pointing at them. I then want to scale the objects by pinching both hands and pulling them apart or closer together (to make an object bigger or smaller).
I also want to move these selected objects by pinching one hand and moving the hand in the air. The object should move from its location according to the hand movement.

~Vulkanos

---

public class LeapMoveObjects : MonoBehaviour
{

	[SerializeField]
	private PinchDetector _pinchDetectorA;

	public PinchDetector PinchDetectorA {
		get {
			return _pinchDetectorA;
		}
		set {
			_pinchDetectorA = value;
		}
	}

	[SerializeField]
	private PinchDetector _pinchDetectorB;

	public PinchDetector PinchDetectorB {
		get {
			return _pinchDetectorB;
		}
		set {
			_pinchDetectorB = value;
		}
	}

	[SerializeField]
	private ExtendedFingerDetector _extendedFinterDetectorL;

	public ExtendedFingerDetector ExtendedFingerDetectorL {
		get {
			return _extendedFinterDetectorL;
		}
		set {
			_extendedFinterDetectorL = value;
		}
	}

	[SerializeField]
	private ExtendedFingerDetector _extendedFinterDetectorR;

	public ExtendedFingerDetector ExtendedFingerDetectorR {
		get {
			return _extendedFinterDetectorR;
		}
		set {
			_extendedFinterDetectorR = value;
		}
	}
	private Finger.FingerType FingerName = Finger.FingerType.TYPE_INDEX;

	public IHandModel HandModelL;
	public IHandModel HandModelR;
	public GameObject selectedObject;
	private GameObject hitObject;
	//if onTarget > 10 hitObject becomes the selectedObject
	private int onTarget = 0;
	public LineRenderer lr;

	private float _defaultNearClip;

	void Start ()
	{

	}

	void Update ()
	{
		bool didUpdate = false;
		if (_pinchDetectorA != null)
			didUpdate |= _pinchDetectorA.DidChangeFromLastFrame;
		if (_pinchDetectorB != null)
			didUpdate |= _pinchDetectorB.DidChangeFromLastFrame;

		if (didUpdate) {
			transform.SetParent (null, true);
		}

		if (_pinchDetectorA != null && _pinchDetectorA.IsActive &&
		     _pinchDetectorB != null && _pinchDetectorB.IsActive) {
			transformDoubleAnchor ();
		} else if (_pinchDetectorA != null && _pinchDetectorA.IsActive) {
			transformSingleAnchor (_pinchDetectorA);
		} else if (_pinchDetectorB != null && _pinchDetectorB.IsActive) {
			transformSingleAnchor (_pinchDetectorB);
		} else if (_extendedFinterDetectorL != null && _extendedFinterDetectorL.IsActive) {
			Hand hand;
			hand = HandModelL.GetLeapHand();
			shootRaycast (hand);
		} else if (_extendedFinterDetectorR != null && _extendedFinterDetectorR.IsActive) {
			Hand hand;
			hand = HandModelR.GetLeapHand();
			shootRaycast (hand);
		} else {
			stopShootingRaycast ();
		}

		if (didUpdate) {
			transform.SetParent (selectedObject.transform, true);
		}
	}

	public Transform getAnchor ()
	{
		return selectedObject.transform;
	}

	public void shootRaycast (Hand hand)
	{
		int selectedFinger = selectedFingerOrdinal();

		Vector3 firePoint = hand.Fingers[selectedFinger].TipPosition.ToVector3();
		lr.enabled = true;
		lr.SetPosition(0, firePoint);
		//Vector3 fingerDirection = lr.transform.forward;
		Vector3 fingerDirection = hand.Fingers[selectedFinger].Bone(Bone.BoneType.TYPE_DISTAL).Direction.ToVector3();
		RaycastHit hit;
		if (Physics.Raycast(firePoint, fingerDirection, out hit, 2000.0f)) { //was something hit?
			fingerDirection = hit.point;
			if (hit.collider.tag == "interactable") {
				if (hitObject != null && hitObject.Equals (hit.collider.gameObject)) {
					onTarget += 1;
				} else {
					hitObject = hit.collider.gameObject;
					onTarget = 0;
				}
			}

			if (onTarget > 10) {
				selectedObject = hitObject;
			}
		}

		lr.SetPosition(1, fingerDirection);
	}

	private int selectedFingerOrdinal(){
		switch(FingerName){
		case Finger.FingerType.TYPE_INDEX:
			return 1;
		case Finger.FingerType.TYPE_MIDDLE:
			return 2;
		case Finger.FingerType.TYPE_PINKY:
			return 4;
		case Finger.FingerType.TYPE_RING:
			return 3;
		case Finger.FingerType.TYPE_THUMB:
			return 0;
		default:
			return 1;
		}
	}

	public void stopShootingRaycast()
	{
		lr.enabled = false;
	}

	private void transformDoubleAnchor ()
	{
		selectedObject.transform.localScale = Vector3.one * Vector3.Distance (_pinchDetectorA.Position, _pinchDetectorB.Position) ;
	}

	private void transformSingleAnchor (PinchDetector singlePinch)
	{
		Vector3 objVectorPos = selectedObject.transform.position;
		objVectorPos.x = singlePinch.transform.position.x;
		objVectorPos.z = singlePinch.transform.position.z;
		selectedObject.transform.position = objVectorPos;
	}
}

[Vulkanos]

I found an answer to my question so Ill post it here in case someone wants to do something like this as well.

The solution was, that I created a separate Transformation without any parent.
I'm then taking the transform of that object as an anchor. (similar to LeapRTS script).

I then changed the code around so my selected object would get the anchor as a parent object.
I'm then changing the position of the anchor object by applying the position of my pinch on it.
Because it's a parent object of selectedObject, selectedObject will move relative to the anchor.
The only thing left to do, was to remove parent of the (currently)selectedObject whenever you want to select another object. (else all the selected objects will be parented to the anchor one by one and eventually you will move them all at once)

Updated Code is here:

using UnityEngine;

namespace Leap.Unity {
/// <summary>
/// Use this component on a Game Object to allow it to be manipulated by a pinch gesture. 
/// The component allows translation and scale of the object.

/// Translate by pinching one hand.
/// Scale by pinching both your hands.

/// Objects can be selected by pointing at them.
/// When pointing with your index finger, a lasser will appear. Use the laser to select objects. //TODO: let the laser appear green when an object was selected

/// </summary>
public class LeapMoveObjects : MonoBehaviour
{

	[SerializeField]
	private PinchDetector _pinchDetectorA;

	public PinchDetector PinchDetectorA {
		get {
			return _pinchDetectorA;
		}
		set {
			_pinchDetectorA = value;
		}
	}

	[SerializeField]
	private PinchDetector _pinchDetectorB;

	public PinchDetector PinchDetectorB {
		get {
			return _pinchDetectorB;
		}
		set {
			_pinchDetectorB = value;
		}
	}

	[SerializeField]
	private ExtendedFingerDetector _extendedFinterDetectorL;

	public ExtendedFingerDetector ExtendedFingerDetectorL {
		get {
			return _extendedFinterDetectorL;
		}
		set {
			_extendedFinterDetectorL = value;
		}
	}

	[SerializeField]
	private ExtendedFingerDetector _extendedFinterDetectorR;

	public ExtendedFingerDetector ExtendedFingerDetectorR {
		get {
			return _extendedFinterDetectorR;
		}
		set {
			_extendedFinterDetectorR = value;
		}
	}

	private Finger.FingerType FingerName = Finger.FingerType.TYPE_INDEX;

	[Range(1,2)]
	public float strength = 2.0f;

	public IHandModel HandModelL;
	public IHandModel HandModelR;
	public GameObject selectedObject;
	private GameObject hitObject;
	//if onTarget > ON_TARGET_THRESHOLD hitObject becomes the selectedObject
	private int onTarget = 0;
	private readonly int ON_TARGET_THRESHOLD = 50;
	public LineRenderer lr;

	private float _defaultNearClip;
	private Transform _anchor;
	private bool _didUpdate;

	void Start ()
	{
		GameObject pinchControl = new GameObject ("RTS Anchor");
		_anchor = pinchControl.transform;
		_anchor.transform.parent = transform.parent;
	}

	void Update ()
	{
		_didUpdate = false;
		if (_pinchDetectorA != null)
			_didUpdate |= _pinchDetectorA.DidChangeFromLastFrame;
		if (_pinchDetectorB != null)
			_didUpdate |= _pinchDetectorB.DidChangeFromLastFrame;

		if (_didUpdate) {
			if (selectedObject != null) {
				selectedObject.transform.SetParent (null, true);
			}
		}

		if (_pinchDetectorA != null && _pinchDetectorA.IsActive &&
		    _pinchDetectorB != null && _pinchDetectorB.IsActive) {
			transformDoubleAnchor ();
		} else if (_pinchDetectorA != null && _pinchDetectorA.IsActive) {
			transformSingleAnchor (_pinchDetectorA);
		} else if (_pinchDetectorB != null && _pinchDetectorB.IsActive) {
			transformSingleAnchor (_pinchDetectorB);
		} else if (_extendedFinterDetectorL != null && _extendedFinterDetectorL.IsActive) {
			Hand hand;
			hand = HandModelL.GetLeapHand ();
			shootRaycast (hand);
		} else if (_extendedFinterDetectorR != null && _extendedFinterDetectorR.IsActive) {
			Hand hand;
			hand = HandModelR.GetLeapHand ();
			shootRaycast (hand);
		} else {
			stopShootingRaycast ();
		}

		if (_didUpdate) {
			selectedObject.transform.parent = _anchor;
		}
	}

	public Transform getAnchor ()
	{
		return selectedObject.transform;
	}

	public void shootRaycast (Hand hand)
	{
		int selectedFinger = selectedFingerOrdinal ();

		Vector3 firePoint = hand.Fingers [selectedFinger].TipPosition.ToVector3 ();
		lr.enabled = true;
		lr.SetPosition (0, firePoint);
		//Vector3 fingerDirection = lr.transform.forward;
		Vector3 fingerDirection = hand.Fingers [selectedFinger].Bone (Bone.BoneType.TYPE_DISTAL).Direction.ToVector3 ();
		RaycastHit hit;
		if (Physics.Raycast (firePoint, fingerDirection, out hit, 2000.0f)) { //was something hit?
			fingerDirection = hit.point;
			if (hit.collider.tag == "interactable") {
				if (hitObject != null && hitObject.Equals (hit.collider.gameObject)) {
					onTarget += 1;
				} else {
					hitObject = hit.collider.gameObject;
					onTarget = 0;
				}
			}

			if (onTarget > ON_TARGET_THRESHOLD) {
				selectedObject.transform.SetParent (null, true);
				selectedObject = hitObject;
			}
		}

		lr.SetPosition (1, fingerDirection);
	}

	private int selectedFingerOrdinal ()
	{
		switch (FingerName) {
		case Finger.FingerType.TYPE_INDEX:
			return 1;
		case Finger.FingerType.TYPE_MIDDLE:
			return 2;
		case Finger.FingerType.TYPE_PINKY:
			return 4;
		case Finger.FingerType.TYPE_RING:
			return 3;
		case Finger.FingerType.TYPE_THUMB:
			return 0;
		default:
			return 1;
		}
	}

	public void stopShootingRaycast ()
	{
		lr.enabled = false;
	}

	private void transformDoubleAnchor ()
	{
		Vector3 rememberAnchor = _anchor.position;
		_anchor.position = selectedObject.transform.position;
		//if the motion is to apprupt and fast, the moddel gets tossed arround
		//you could also use a Vector.one for this opperation, however tests have proofen it better to half the values
		_anchor.localScale = new Vector3(0.5f,0.5f,0.5f) * Vector3.Distance(_pinchDetectorA.Position, _pinchDetectorB.Position) ; 
	}

	private void transformSingleAnchor (PinchDetector singlePinch)
	{
		Vector3 pinchPoint = singlePinch.Position * strength;
		pinchPoint.y = _anchor.position.y;

		_anchor.position = pinchPoint;
	}
}

}

[rahb3rt]

So here is a stupid question for you. After you wrote the script.. what did you have to attach it to to make it work?

Trying to do something similar with raycasts and every time I get a null reference to my leap hands.

Thanks!

[Vulkanos]

I attached the script to an empty Object which holds all moveable objects as a parent.

In your LMHeadMountedRig - HandModels. There should be 2 Hand scripts (Left & Right).
Attach a Hand Attachment Script to both of them.
Attach two new transforms for each hand. One on Index, one on pinch point.

Attach an Extended Finger Detector on the Index finger transfroms and only select Index as extended.
Attach a Pinch Detector on the Pinch point transforms.

Then just drag and drop the correct detectors and hand models onto the LeapMoveObjects script.

And it should work!

~Vulkanos

[jchernick2010]

Hi Vulkanos,

I am trying to follow your instructions but am getting stuck.

I ma getting stuck at attaching two new transforms for each hand. one on index make sense but how do I attached a new transform on pinch point? by pinch point do you mean thumb point?

thanks for your help.

[jchernick2010]

Hi Vulkanos,

I got this to work but it seems to be glitch in terms of two handed rotation. it scales fine and rotates fine with one hand but then when doing two handed rotation it glitches and jumps out of screen. any ideas?

Thanks

[Vulkanos]

Great to hear someone actually makes use of this
For two handed rotation I would recommend to view the LeapRTS script.

Ill upload it for you here. Its from the LeapMotionModules - DetectionExamples - Scripts.
This one also has a scene "PinchMovementDemo" where it demonstates the use of the LeapRTS script.

https://uploadfiles.io/s8ixp

[jchernick2010]

Thanks!

Do you know if the RTS script is still supported in newer versions of Unity?

I appreciate the help.

[Vulkanos]

Just loaded the scene (PinchMovementDemo under DetectionExamples - Scenes) and hooked up my Leap - oh boy it has been some time.

Still works like a charm! Smooth movement and rotation with one and two hands for me.

~Vulkanos