Unity drag doesn't work, object moves away from the pointer

Question

I've attached the following script to an Image inside the Canvas :

public class DragMe : MonoBehaviour, IDragHandler
{
    public void OnDrag(PointerEventData eventData)
    {
        this.transform.localPosition += (Vector3)eventData.delta;
    }
}

The problem is, as I drag further, the Image goes away more and more from under the pointer. When I drag back to the start position the Image comes back where it was under the finger/pointer.

changing the code to:

this.transform.position = eventData.position;

causes the object to jump away somewhere else.

Any help is much appreciated.

Update: Guys, if you read my code and the supposed duplicate question you see their answer is my question! But it has an issue, i.e. the object doesn't stay under the dragging finger/pointer and keeps going away further as you keep dragging!

Update 2: Image:

Canvas:

Camera:

https://stackoverflow.com/questions/37473802/unity3d-ui-calculation-for-position-dragging-an-item — aybe, Apr 07 '19 at 03:53
Possible duplicate of [Unity3D UI, calculation for position dragging an item?](https://stackoverflow.com/questions/37473802/unity3d-ui-calculation-for-position-dragging-an-item) — Draco18s no longer trusts SE, Apr 07 '19 at 04:10
@Draco18s It is the same code as in my question, but it has an issue that they haven't noticed I guess. — Blendester, Apr 07 '19 at 04:12
Please show the transform properties of the image and also the canvas. — shingo, Apr 07 '19 at 04:26
@shingo Please have a look at the screenshots. as I drag, the object doesn't stay under my finger, like if it has a different scaling — Blendester, Apr 07 '19 at 05:30

score 3 · Accepted Answer · answered Apr 07 '19 at 06:06

It's better to use Screen Space - Overlay if the camera's viewport is unchanged. Then following code will work:

this.transform.position = eventData.position;

To use Screen Space - Camera, you need transform the event position into the camera space:

Vector3 position = eventData.position;
var canvas = image.canvas;
position.z = canvas.planeDistance;
image.transform.position = canvas.worldCamera.ScreenToWorldPoint(position);

Unity drag doesn't work, object moves away from the pointer

1 Answers1