Scaling issue using a GUITexture on a sprite object in unity

Questions & Answers
1

I’m trying to make a Kinect game using MS-SDK wrapper from the Asset store in Unity, In the kinect manager script the Hand Cursor object is where you can set the gameObject you want to act as a cursor.

The example provided by MSSDK gesture demo uses a GUITexture as the Hand cursor, however to be able to detect collisions, the box collider component attached to the hand cursor needs a transform scale value set to atleast 0.1, but setting the scale value causes the Texture to appear very large.

I would prefer to use sprites over GUITexture, since most of the gameObjects will be sprites but the movement as a sprite object is very limited, the object doesnt really move as much as the hand.

The same issue occurs, if I create a sprite and add an GUITexture component, or if I just use a sprite then it doesn’t move with my hand properly (very less translation).

In short, I want to be able to use a hand cursor and detect collision with other sprites in the game.

To understand a bit about whats going on with the code, here’s a snippet

RightHandCursor Gesture detection:

// check for RightHandCursor
			case Gestures.RightHandCursor:
				switch(gestureData.state)
				{
					case 0:  // gesture detection - phase 1 (perpetual)
						if(jointsTracked[rightHandIndex] && jointsTracked[rightHipIndex] &&
							(jointsPos[rightHandIndex].y - jointsPos[rightHipIndex].y) > -0.1f)
						{
							gestureData.joint = rightHandIndex;
							gestureData.timestamp = timestamp;
							//gestureData.jointPos = jointsPos[rightHandIndex];
							SetScreenPos(userId, ref gestureData, ref jointsPos, ref jointsTracked);
							gestureData.progress = 0.7f;
						}
						else
						{
							// cancel the gesture
							//SetGestureCancelled(ref gestureData);
							gestureData.progress = 0f;
						}
						break;
				
				}
				break;

The SetScreenPos function:

private static void SetScreenPos(uint userId, ref GestureData gestureData, ref Vector3[] jointsPos, ref bool[] jointsTracked)
	{
		Vector3 handPos = jointsPos[rightHandIndex];
		bool calculateCoords = false;
		
		if(gestureData.joint == rightHandIndex)
		{
			if(jointsTracked[rightHandIndex] /**&& jointsTracked[rightElbowIndex] && jointsTracked[rightShoulderIndex]*/)
			{
				calculateCoords = true;
			}
		}
		else if(gestureData.joint == leftHandIndex)
		{
			if(jointsTracked[leftHandIndex] /**&& jointsTracked[leftElbowIndex] && jointsTracked[leftShoulderIndex]*/)
			{
				handPos = jointsPos[leftHandIndex];				
				calculateCoords = true;
			}
		}
		if(calculateCoords)
		{			
			if(jointsTracked[hipCenterIndex] && jointsTracked[shoulderCenterIndex] && 
				jointsTracked[leftShoulderIndex] && jointsTracked[rightShoulderIndex])
			{
				Vector3 neckToHips = jointsPos[shoulderCenterIndex] - jointsPos[hipCenterIndex];
				Vector3 rightToLeft = jointsPos[rightShoulderIndex] - jointsPos[leftShoulderIndex];
				
				gestureData.tagVector2.x = rightToLeft.x; // * 1.2f;
				gestureData.tagVector2.y = neckToHips.y; // * 1.2f;
				
				if(gestureData.joint == rightHandIndex)
				{
					gestureData.tagVector.x = jointsPos[rightShoulderIndex].x - gestureData.tagVector2.x / 2;
					gestureData.tagVector.y = jointsPos[hipCenterIndex].y;
				}
				else
				{
					gestureData.tagVector.x = jointsPos[leftShoulderIndex].x - gestureData.tagVector2.x / 2;
					gestureData.tagVector.y = jointsPos[hipCenterIndex].y;
				}
			}
			
			if(gestureData.tagVector2.x != 0 && gestureData.tagVector2.y != 0)
			{
				Vector3 relHandPos = handPos - gestureData.tagVector;
				gestureData.screenPos.x = Mathf.Clamp01(relHandPos.x / gestureData.tagVector2.x);
				gestureData.screenPos.y = Mathf.Clamp01(relHandPos.y / gestureData.tagVector2.y);
	
			}
		}
	}

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2

GUITextures live in Viewport space. Viewport space starts at (0,0) in the lower left and go to (1,1) in upper right. So to use a sprite, you need to modify the conversion to use world coordinates. In the cursor code you will likely see a ScreenToViewportPoint() call. This call needs to be ScreenToWorldPoint().