This repository is based on the following:
https://github.com/wacki/Unity-VRInputModule
The goal is a laser pointer for a VR experience with HTC Vive using Unity and SteamVR 2.0.
To achieve this, some scripts had to be modified.
Also, this repository will only focus on the HTC Vive with SteamVR.
(suggested)
If you are using the prefab provided by Valve,
simply add the LaserPointerInputModule script to the game object InputModule inside the "Player" prefab.
Then drag the laser pointer pickup prefab (Assets/VRInputModule/Prefabs/Pickup/Pointer/PointerPickup) into the scene.
If you are using the prefab provided by Valve,
simply add the LaserPointerInputModule script to the game object InputModule inside the "Player" prefab.
There is already a EventSystem script attached to it.
Ensure to enable Send Navigation Events on it.
After that, you can add the ViveUILaserPointer script to the desired controller/hand.
They are usually located here in the editor game object hierarchy: Player/SteamVRObjects/.
Their name is either LeftHand or RightHand.
INFO: You don't have to add the script directly to them if you want!
You can simply add the script to any game object.
But something you always have to do is selecting the desired controller on the script!
Ensure you use Valve's Hand script for your controllers
and that you add the LaserPointerInputModule script to the game object that holds an EventSystem component!
After that, you can add the ViveUILaserPointer script to the desired controller/hand as explained in "Option 1".
I created a new scene and added the script but nothing is working!
Well, there could be several reasons for this.
One important thing that could be responsible for this behaviour is that
there is no EventSystem component attached to the game object you have the LaserPointerInputModule attached to.
Another one could be that there are multiple EventSystem components in the scene
that prevent the call of the Process function.
I created a controller pickup functionality, but changing items immediately removes the selected one?
I had this problem and searched for a solution about half an hour or longer...
For me, it was no bug in my code. It was simply caused by the property Hide Hand On Attach.
This property is provided by Valves Interactable script and seems to cause problems switching items.
I suggest to hide both, the controller and the hand to avoid such bugs.
- fix: visible hit point (issue was just the size, no bug)
- added SteamVR pickup functionality (new scripts: ViveUILaserPointerPickup and UILaserPointerPickup)
- UILaserPointerPickup does the exact same as UILaserPointer BUT does not use the "Update" function (only difference)
- added prefabs/examples for the pickup functionality
- code modied to function as supposed.
- added enable/disable feature for the laser pointer
- added sample scene (see
Scenesfolder)
The code and functionality is currently not tested.
Testing and improvements will follow in some days.
(At least how I think it works from inspecting the code... - correct me please if I am wrong)
First, the laser pointer will cast a ray.
To cast the ray, we use Physics.Raycast.
As you can read in the documentation, this casts a ray against all colliders in the scene.
This type of ray does not hit any UI element.
It only hits/detects objects that have a collider component added to them.
But we don't really want a Collider for UI Elements.
They could block other objects in VR.
So how are we detecting if we hit a UI-Element?
The first ray is only to detect/set the correct distance to objects in the world we hit.
It has nothing to do with functionality on the user interface.
To detect hits with UI elements, there is another ray.
This ray is casted different to the previous one.
To cast it, we take the EventSystem from the BaseInputModule and use EventSystem.RaycastAll.
As you can read in the docs, it casts a ray into the scene using all configured BaseRaycasters.
And as you can read there as well, default Raycasters are PhysicsRaycaster, Physics2DRaycaster, GraphicRaycaster.
Calling the beforementioned method requires a PointerEventData to be passed.
The position of this data (pointerEvent.position) is set by us using a self-created UICamera.
This camera is set for each canvas in the world to be the Event Camera or also known as Canvas.worldCamera.
Having a look at the docs as well tells us the following about it:
Also used as the Camera that events will be sent through for a World Space [[Canvas].).
As we always make this camera look at the same as our laser points at,
we can simply use the center of what the camera is seeing as done in this line of code:
data.pointerEvent.position = new Vector2(UICamera.pixelWidth * 0.5f, UICamera.pixelHeight * 0.5f);
As a result, we can get the correct UI element hit by the ray.
We then simply use BaseInputModule.FindFirstRaycast to get the first valid raycast result.
After that, we check if the hit distance is less than the distance we got by the first raycast and update the length of the laser accordingly.
We then handle a bunch of events. For example the HandlePointerExitAndEnter event.
Depending on the laser inputs (toggle button pressed...) we use ExecuteEvents to notify affected game objects about events like pointer down, up, click or drag.
- Fix: UI-Element still selected after laser pointer is deactivated while pointing at it