Hover Effects

The VisionOSHoverEffect component provides a hint to the platform to apply a system hover effect when the user is hovering over this object. This is typically used to provide a visual cue to the user that the object is interactive. This effect gets triggered by gaze or a hand poke. The effect is applied to the object that is being hovered over, and not the object that is doing the hovering.

For privacy reasons, visionOS does not permit apps access to user gaze directly. However, it is often helpful to visually highlight objects at which the user is gazing in order to hint which object will receive input if the user performs a pinch gesture. To this end, Unity PolySpatial provides a VisionOSHoverEffect component for visionOS, which can be added to GameObjects that might receive input via gaze. The presence of this component instructs the host platform (RealityKit) to apply a coloration effect to GameObject's MeshRenderer any time the user's gaze ray intersects its corresponding collider(s).

Three components must be present to achieve the hover effect:

• A VisionOSHoverEffect component indicates that the GameObject and its descendants should display an effect when hovered.
• A Collider component on the same GameObject as the VisionOSHoverEffect defines the collision shape against which the gaze ray is cast.
• A MeshRenderer provides the mesh and geometry on which the coloration affect is applied. The MeshRenderer may be on the GameObject containing the VisionOSHoverEffect and Collider components or on any of its descendants.

The VisionOS Hover Effect component contains following properties:

Property	Description
Type	The type of hover effect to use: Spotlight for a spotlight around the hovered position, Highlight for the spotlight effect plus a uniform highlight, or Shader for a hover effect defined by the PolySpatial Hover State node.
Color	The color of the effect, when using the Spotlight or Highlight types.
Intensity Multiplier	The intensity of the effect, when using the Spotlight or Highlight types.
Fade In Duration	The duration in seconds over which the effect fades in, when using the Shader type.
Fade Out Duration	The duration in seconds over which the effect fades out, when using the Shader type.

Skinned Mesh Renderers

To display a hover effect on SkinnedMeshRenderer components, the VisionOSHoverEffect and Collider components must be present on the parent of the SkinnedMeshRenderer GameObject (or any of its ancestors).

PolySpatial Hover State shader graph node

Within shader graphs, the hover state may be accessed using the PolySpatial Hover State node. This node provides the following outputs:

Output	Type	Description
Intensity	Float	The current hover intensity. This fades in and out according to the Fade In Duration and Fade Out Duration properties.
Position	Vector 3	The position of the hover point.
Time Since Hover Start	Float	The time in seconds since the hover effect started.
Is Active	Boolean	Whether or not the hover effect is currently active.

UGUI Selectable hover transitions

On visionOS, hover transitions for certain Selectable objects (Button, Dropdown, TMP_Dropdown, InputField, TMP_InputField, Scrollbar, Slider, and Toggle) are automatically handled by adding a hover effect component to the Selectable's targetGraphic and using the PolySpatial Hover State shader graph node in the PolySpatial UI image shader graph (Packages/PolySpatial/Resources/Shaders/MaskingShader.shadergraph) to switch between the normal Color and a separate HoverColor property. Note that only Color Tint transitions are supported for hover through this method and that any custom UI shaders (that is, shaders other than UI/Default) must replicate the properties and hover state functionality of MaskingShader in order to show transitions on hover.