New Events System Issue when Panning Camera..

Hi Guys,

Im having an issue trying to code up a camera panning solution using the new ui events system. Check out this video first:

As you can see when I pan the camera the HUD jitters as if its position is off by one frame.

I have setup my canvas to be screen space camera as I need some game stuff to be rendered in front of it.



If I set the canvas to be screen space overlay then the problem doesnt present itself.

My panner object is a large 2d collider game object that has its z order set behind the game objects:



The Panner code is very simple:

public class Panner : MonoBehaviour, IDragHandler
{
public Transform target;
private float unit;

public void Awake()
{
var p1 = UnityEngine.Camera.main.ScreenToWorldPoint(Vector3.zero);
var p2 = UnityEngine.Camera.main.ScreenToWorldPoint(Vector3.right);
unit = Vector3.Distance(p1, p2);
}

public void OnDrag(PointerEventData data)
{
target.Translate(-data.delta.x * unit, -data.delta.y * unit, 0f);
}
}

Does anyone have any idea why its jittering?

I thought it may be an update order issue so I tried moving the translate code out of the panner into an "LateUpdate" method but it still had the same problem.

EDIT: I have created this simple project to show the problem: https://www.dropbox.com/s/yoxw0e6tbbu87ii/UIJiterProblem.zip?dl=0

Cheers for any advice,
Mike

 

Try adding Canvas.ForceUpdateCanvases after you have moved the canvas.

 

Im not actually translating the Canvas, im translating the Camera transform.

Despite that I tried Canvas.ForceUpdateCanvases and it didn't work plus it seems to "increase the sensitivity" i.e. when you move the mouse 1px it translates by 2, probably because the drag event is now being fired twice.

 

No one have any ideas? Is there a way to change the order in which the events are processed? Or is this a bug?

 

It's the weekend: Wait until the devs who actually wrote the code come back and see this. The rest of us are still learning the system by trial-and-error-and-partial-sourcecode.

 

Good point Worst comes to the worst ill manually implement panning / zooming without using the new events system.

 

How are the two items in the video related in hierarxhy? And how related to camera?
Is one a child of other or camera?

also does canvas have pixel perfect on? Could that be the culprit? Idk

 

Nope, pixel perfect is not on. I have created this stripped-down project which shows the problem:

https://www.dropbox.com/s/yoxw0e6tbbu87ii/UIJiterProblem.zip?dl=0

 

Sure

 

Okay, I have sent a bug via the unity bug reporter: http://fogbugz.unity3d.com/default.asp?633562_q5q2soe3ehh3pt87

 

Any update on this bug? I'm suffering from the same issue...

 

I have a very similar issue. Knowing it's a bug is kind of a good thing, sort of, since when it's fixed it should work. hopefully

http://forum.unity3d.com/threads/he...-moves-other-such-issues.274976/#post-1815277

 

This got fixed in one of the late betas of 4.6, it works fine for me now.

 

Code (CSharp):

1. var p1 = UnityEngine.Camera.main.ScreenToWorldPoint(Vector3.zero);
2. var p2 = UnityEngine.Camera.main.ScreenToWorldPoint(Vector3.right);
3. unit = Vector3.Distance(p1, p2);

can anyone explain what this code is for and why my orthographic 2d camera pan does not work without multiplying delta by this 'length of a unity vector'?

it works and that is great but took me a while to 'figure it out'

thanks