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Touched object snaps to center when dragged
I already found a very good script in the forum concerning dragging a 3D object on an xz-Plane!
http://answers.unity3d.com/questions/566327/drag-object-relative-to-camera.html
private float maxPickingDistance = 10000;// increase if needed, depending on your scene size
private Vector3 startPos;
private Vector3 offset;
private Transform pickedObject = null;
// Update is called once per frame
void Update ()
{
foreach (Touch touch in Input.touches)
{
//Create horizontal plane
Plane horPlane = new Plane(Vector3.up, Vector3.zero);
//Gets the ray at position where the screen is touched
Ray ray = Camera.main.ScreenPointToRay(touch.position);
if (touch.phase == TouchPhase.Began)
{
RaycastHit hit = new RaycastHit();
if (Physics.Raycast(ray, out hit, maxPickingDistance))
{
pickedObject = hit.transform;
startPos = touch.position;
}
else
{
pickedObject = null;
}
}
else if (touch.phase == TouchPhase.Moved)
{
if (pickedObject != null)
{
float distance1 = 0f;
//offset = pickedObject.transform.position - Camera.main.ScreenToWorldPoint(new Vector3(startPos.x, startPos.y,pickedObject.transform.position.z));
if (horPlane.Raycast(ray, out distance1))
{
pickedObject.transform.position = ray.GetPoint(distance1);
}
}
}
else if (touch.phase == TouchPhase.Ended)
{
pickedObject = null;
}
}
}
}
I just can't figure out how to fix the snapping to the center of the object when i start dragging. I found several Q/A in this forum where an offset is mentioned but when i try to implement any of those ideas in the code the debugger throws exceptions. I would appreciate any ideas!
Thanks in advance!
milla
Answer by _milla_ · Jul 10, 2014 at 07:58 PM
Alright - i tried again figuring out, how i can implement the offset. I almost got it. There is just one thing i could not get fixed. The setup allows dragging on the xz-plane. When I touch an object near the plane (y almost 0) and start dragging, it seams to work (object does not jump to my finger and is dragged very smooth). BUT when i touch the object at the top (e.g. at the tip of a tower) the more i drag it, the more it moves away from my touch point. It moves in the same direction, but the distance between object and touch becomes bigger the longer i drag it.
Can anybody help me or give some advices? Thanks in advance!!!
milla
Here is the code:
using UnityEngine;
using System.Collections;
//code from http://answers.unity3d.com/questions/566327/drag-object-relative-to-camera.html
public class MyDragBehaviour2 : MonoBehaviour
{
private float maxPickingDistance = 10000;// increase if needed, depending on your scene size
private Vector3 offset;
private float distance1;
private Transform pickedObject = null;
// Update is called once per frame
void Update ()
{
foreach (Touch touch in Input.touches)
{
//Create horizontal plane
Plane horPlane = new Plane(Vector3.up, Vector3.zero);
//Gets the ray at position where the screen is touched
Ray ray = Camera.main.ScreenPointToRay(touch.position);
if (touch.phase == TouchPhase.Began)
{
RaycastHit hit = new RaycastHit();
if (Physics.Raycast(ray, out hit, maxPickingDistance))
{
horPlane.Raycast(ray, out distance1);
pickedObject = hit.transform;
offset = pickedObject.transform.position - ray.GetPoint(distance1);
}
else
{
pickedObject = null;
}
}
else if (touch.phase == TouchPhase.Moved)
{
if (pickedObject != null)
{
float distance1 = 0f;
if (horPlane.Raycast(ray, out distance1))
{
pickedObject.transform.position = ray.GetPoint(distance1)+offset;
}
}
}
else if (touch.phase == TouchPhase.Ended)
{
pickedObject = null;
}
}
}
}
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