---
title: groupID
framework: realitykit
role: symbol
role_heading: Instance Property
path: realitykit/hovereffectcomponent/hovereffect-swift.struct/groupid
---

# groupID

An optional group identifier for the hover effect.

## Declaration

```swift
var groupID: HoverEffectComponent.GroupID? { get set }
```

## Discussion

Discussion The system activates the hover effect entities that have the same HoverEffectComponent.GroupID instance at the same time when a person looks at it or hovers over any entity in the group. Activating Hover Effects The system activates hover effect entities with a groupID independently from the hierarchical activation behavior. let boxSize = SIMD3<Float>(0.3, 0.1, 0.05) let modelComponent = ModelComponent(     mesh: MeshResource.generateBox(size: boxSize, cornerRadius: 0.2),     materials: [SimpleMaterial(color: .black, roughness: 0.5, isMetallic: false)] ) let collisionComponent = CollisionComponent(     shapes: [ShapeResource.generateBox(size: boxSize)] ) let inputTargetComponent = InputTargetComponent()

let hoverEntityA = Entity(components:                             modelComponent, collisionComponent, inputTargetComponent ) let hoverEntityB = hoverEntityA.clone(recursive: true) hoverEntityB.position.x = -0.2 hoverEntityB.position.y = -0.15

let hoverEntityBB = hoverEntityA.clone(recursive: true) hoverEntityBB.position.y = -0.15

let hoverEntityC = hoverEntityA.clone(recursive: true) hoverEntityC.position.x = 0.2 hoverEntityC.position.y = -0.15

content.add(hoverEntityA) hoverEntityA.addChild(hoverEntityB) hoverEntityB.addChild(hoverEntityBB) hoverEntityA.addChild(hoverEntityC)

// Create hover effect component for the top entity in the scene. let hoverA = HoverEffectComponent(     .highlight(HoverEffectComponent.HighlightHoverEffectStyle(         color: .green, strength: 2.0         ))) hoverEntityA.components.set(hoverA)

// Create hover effect components for the two children on the left side. var hoverB = HoverEffectComponent(     .highlight(HoverEffectComponent.HighlightHoverEffectStyle(         color: .yellow, strength: 2.0         )))

var hoverBB = HoverEffectComponent(     .highlight(HoverEffectComponent.HighlightHoverEffectStyle(         color: .orange, strength: 2.0         )))

// Create a `HoverEffectComponent.GroupID` instance for the children on the left side let leftGroupId = HoverEffectComponent.GroupID() hoverB.hoverEffect.groupID = leftGroupId hoverBB.hoverEffect.groupID = leftGroupId hoverEntityB.components.set(hoverB) hoverEntityBB.components.set(hoverBB)

In this example, the top entity, entityA, doesn’t have a group identifier. However, the left side entities, entityB and entityBB, have the same HoverEffectComponent.GroupID instance. The top entity entityA and its right child entityC both glow when a person activates either one in the right side hierarchical branch. However, the left child entityB and its descendent entityBB glow only when a person activates either one of them.