# init(shaderGraph:inputValues:constantValues:) Creates a descriptor with the given shader graph and optional initial values. ``` init(shaderGraph: ShaderGraph, inputValues: [String : MaterialParameters.Value] = [:], constantValues: MTLFunctionConstantValues = .init()) ``` ## Parameters `shaderGraph` The shader graph that describes the program’s surface and, optionally, geometry-modifier shading. `inputValues` Initial values for the inputs the shader graph declares. Defaults to an empty dictionary, leaving each input at its declared default. `constantValues` Values for the function-constant inputs the shader graph declares. Defaults to an empty `MTLFunctionConstantValues`, leaving each function constant at its declared default. --- 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)