# BlendShapeWeights A set of animatable weight values that collectively represent the blending amounts for all the blend shapes’ blend targets. ``` struct BlendShapeWeights ``` ## Topics ### Operators [`static func == (BlendShapeWeights, BlendShapeWeights) -> Bool`](/documentation/RealityKit/BlendShapeWeights/==(_:_:)) Returns a Boolean value that indicates whether two collections of weights are equal. ### Initializers [`init()`](/documentation/RealityKit/BlendShapeWeights/init()) Initializes a collection of animatable weights for a blend shape. [`init(S)`](/documentation/RealityKit/BlendShapeWeights/init(_:)) Initializes a collection of weights for a single blend shape. [`init(arrayLiteral: Float...)`](/documentation/RealityKit/BlendShapeWeights/init(arrayLiteral:)) Creates a collection of animatable weights using the argument elements for a blend shape. ### Instance Properties [`var endIndex: BlendShapeWeights.Index`](/documentation/RealityKit/BlendShapeWeights/endIndex) An index to the last weight in the collection. [`var startIndex: BlendShapeWeights.Index`](/documentation/RealityKit/BlendShapeWeights/startIndex) An index to the first weight in the collection. ### Instance Methods [`func index(after: BlendShapeWeights.Index) -> BlendShapeWeights.Index`](/documentation/RealityKit/BlendShapeWeights/index(after:)) Returns the position in the sequence of the weight that follows the given position. [`func index(before: BlendShapeWeights.Index) -> BlendShapeWeights.Index`](/documentation/RealityKit/BlendShapeWeights/index(before:)) Returns the position in the sequence of the weight that preceeds the given position. ### Subscripts [`subscript(BlendShapeWeights.Index) -> Float`](/documentation/RealityKit/BlendShapeWeights/subscript(_:)) Accesses a single weight in the collection at the given index. ### Type Aliases [`typealias ArrayLiteralElement`](/documentation/RealityKit/BlendShapeWeights/ArrayLiteralElement) The type of the elements of an array literal. [`typealias Element`](/documentation/RealityKit/BlendShapeWeights/Element) An individual weight in the collection. [`typealias Index`](/documentation/RealityKit/BlendShapeWeights/Index) A position of an individual weight in the collection. ## Relationships ### Conforms To [`ExpressibleByArrayLiteral`](/documentation/Swift/ExpressibleByArrayLiteral) [`MutableCollection`](/documentation/Swift/MutableCollection) [`BidirectionalCollection`](/documentation/Swift/BidirectionalCollection) [`Equatable`](/documentation/Swift/Equatable) [`AnimatableData`](/documentation/RealityKit/AnimatableData) [`Encodable`](/documentation/Swift/Encodable) [`Collection`](/documentation/Swift/Collection) [`Sequence`](/documentation/Swift/Sequence) [`Escapable`](/documentation/Swift/Escapable) [`Decodable`](/documentation/Swift/Decodable) [`Copyable`](/documentation/Swift/Copyable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)