Touch an object

Unity Engine
,
1

How is it possible to detect if a Touch is touching an object? I tried to compare the positions without any luck…

2

I think you can use OnMouseDown (). I’m pretty sure its functionality was changed to support touches on Iphone.

3

You will need to shoot a ray from screen space to world space. Luckily Unity made this very easy for you:

Ray mouseRay = Camera.main.ScreenPointToRay(Input.mousePosition);
RaycastHit[] hitInfo;
hitInfo = Physics.RaycastAll(mouseRay, Mathf.Infinity);

hitInfo will contain all the objects you are touching, not just the closest one.
You could rewrite this to use touches for multitouch support.[/code]

4

Thanks, but I cant get this to work, how would I make the check to see if it is the object which has the script on it, that i’m currently touching?

5

Well you could go the other way around, by checking from ‘within’ the object if its being touched.

It would be something like:

		Ray mouseRay = Camera.main.ScreenPointToRay(Input.mousePosition);
		
		RaycastHit hitInfo;
		if(collider.Raycast(mouseRay, out hitInfo, Mathf.Infinity))
		{
			//Mouseover	this gameobject/collider!
		}
6

That worked :slight_smile: However is there a way to make it more sensetive? the object has to be hit very precisely to make it respond.

7

You could make the collider bigger so you can touch it easier :slight_smile:

8

Yea but that would also make it easier for other objects to hit it. So I tried to make an empty child with a bigger collider and then try to get the childs collider instead.

It work when using the finger, but the other objects react to the child too. Is there a way for them to ignore the childs collider?

9

You can use Physics.IgnoreCollision(childCollider, everyoneElse) or an easier method would be to make the child collider a trigger, because rays collide with triggers, but normal objects don’t so the rest of your objs would simply pass through the bigger collider.

10

The trigger solved it :slight_smile: thanks