problem with Physics.Raycast

Unity Engine
1

Hi,

Im using this code on a simple slider as per the help tutorial here - http://www.binpress.com/tutorial/unity3d-touch-input/133

However, there is a problem with the line:

if (Physics.Raycast(screenRay, out hit))

It doesnt seem to be recognising this condition. If I move the print statement above the if statement, it prints just fine, so Im sure its got to do with this line.

Any ideas what might be wrong?

        if(nbTouches > 0)
        {
            for (int i = 0; i < nbTouches; i++)
            {
                Touch touch = Input.GetTouch(i);
             
                if(touch.phase == TouchPhase.Began)
                {
                    Ray screenRay = Camera.main.ScreenPointToRay(touch.position);

                    RaycastHit hit;
                    if (Physics.Raycast(screenRay, out hit))
                    {
                        print("User tapped on game object " + hit.collider.gameObject.name);
                        //handleTap(hit.collider.gameObject);
                    }
                }
             
            }
        }
2

The object you click…it has a collider?

3

Hi SubZeroGaming,

Im wondering how I can add a collider? Should I add a box collider exactly the same size as the slider?

    void OnGUI () {

        hSlideValue= GUI.HorizontalSlider(new Rect(25,25,100,30),hSlideValue,0.0f,1.0f);   
 
    }
4

ooh, are you trying to touch a UI element??

For that, you need to use the Event system and check the current Event e if you’re using the OnGUI system…

which brings up the question, why are you using the OnGUI system? UGUI is 100% better and more efficient.

5

Im totally confused regarding UGUI.

Also, Ive made another script where I create lots of buttons and resize them at runtime (based on the canvas size). However, I cannot seem to run this with UGUI. Are there any good tuts on dynamically scripting UGUI and also creating prefabs and referencing them in code?

6

Eh, I’m sure there are.

In the mean time, I believe what you can use is void OnMouseDown(). It’s a unity function that checks if you clicked over a collider or I believe, a UI element. Give that a try.