UI Selection from Vive controller raycast

Does anyone know how to get a raycast (laser pointer) to register which world space UI component is currently being pointed at.

I'm not looking for gaze input but for a raycast from the controller?

 

Hey did you ever manage to find anything out about this?

 

You could add a Box-Collider to your Canvas-Element, which you can use as raycast target. Then you simply add something like this to your vive controller gameobject.

void Update () {

RaycastHit raycastHit;
GameObject gameObject = null;
if(Physics.Raycast(transform.position, transform.forward, out raycastHit))
{
gameObject = raycastHit.collider.gameObject;

//Do sth. with the found GameObject here
}
}

 

Is that the best way of doing it? In an update loop like that?

 

You might want to use FixedUpdate for a raycast? But otherwise, if you don't like Update, you could also use a collider on your controller, and other object - and set it to trigger. Something like:

private void OnTriggerEnter(Collider other)
{
if (other.gameObject.tag == "controller")
{

}
}

 

Using the physics raycasting isn't the best way to do this, not to mention it's cumbersome putting colliders all over UI elements, you should making an input module instead. This way you can just attach it to your event sytem. I would look over Unity's source to the standalone input module but in general you would then just need to do the following.

Code (CSharp):

1. eventSystem.RaycastAll(eventData, m_RaycastResultCache);
2. result = FindFirstRaycast(m_RaycastResultCache);
3. m_RaycastResultCache.Clear();

 

What is eventData? I see PointerEventData but don't understand where that comes from? How do you get PointerEventData from SteamVR?

 

PointerEventData is correct. In normal games it's used from a mouse cursor in relation to the camera but it's generic enough for you to populate with whatever you want. Basically you create one and then populate it with the data from what you are using (HMD if it's gaze based or the controller if it's laser pointer based). That way you can just use a graphics raycaster like Unity does by default and don't have to add colliders all over the UI.

 

Thanks, I believe I am doing something similar to that already and am able to click buttons using IPointerClickHandler .OnPointerClick. All items still require physics colliders, But I still don't understand how to set cursor positions on inputs or drag scrollbars/lists. And I definitely don't understand how to project a GraphicsRaycaster from a VR controllers's tip to the UI plane in world space without using cameras.

 

Waiting for a resolution to this as I'm having the same issue