Flashlight
Overview
The flashlight technique allows a user to select objects with less precision required by a ray-cast. Like a real flashlight a cone volume is projected out of the controller. A user can then select an object by hovering over it with the flashlight.
There are two ways to select between objects if multiple are encompassed by the flashlight:
- If multiple objects are in the volume the one that is closer to the centre line of the cone is selected.
- If the distance between the objects to the centre line are the same then the object closest to the controller is selected.
Source paper of the technique
Liang, J., and M. Green (1994). “JDCAD: A Highly Interactive 3D Modeling System.” Computers and Graphics 18(4): 499–506.
Use by manually attaching
To manually attach the Flashlight to the Camerarig VR components if the auto-attach fails for each hand:
- Drag onto Flashlight script:
- Relevant controller onto ObjectAttachedTo and Tracked Obj
- Drag onto Flashlight Selection
- Relevant controller onto TheController
- Drag Left and Right controller in the flashlight controller script to the Left and Right VR controllers
Inspector parameters
For Flashlight Script:
| Parameter | Default | Description |
|---|---|---|
| Transparency | 0.5 | The level of transparency the cone volume is |
| The Colour | Black | The colour of the cone volume |
For Flashlight Selection Script:
| Parameter | Default | Description |
|---|---|---|
| Interaction Layers | PickableObject | The layers that the technique can interact with |
| Interaction Type | Manipulation | When set to manipulation Flashlight can move objects via fixed joints. When pure selection it will just send an event that it has selected and place the object into a public variable. |
| Selection | None | The currently selected object |
| Object Hovered Over | None | The object currently hovered over |
| Selected Object() | Empty | Event Invoked when an object is selected |
| Hovered() | Empty | Event Invoked when an object is hovered over |
| UnHovered() | Empty | Event Invoked when an object ceases being hovered over |
Test/Example scenes
Major example scene under:
- Assets/Technique Example Scenes/Scenes/FlashlightExample