---
title: constantValues
framework: realitykit
role: symbol
role_heading: Instance Property
path: realitykit/portalmaterial/program-swift.struct/descriptor-swift.struct/constantvalues
---

# constantValues

Values for the function constant inputs declared in shaderGraph.

## Declaration

```swift
var constantValues: MTLFunctionConstantValues
```

## Discussion

Discussion Function constants are compiled directly into the shader and cannot be changed after the program is created.

## See Also

### Configuring the shader program

- [shaderGraph](realitykit/portalmaterial/program-swift.struct/descriptor-swift.struct/shadergraph.md)
- [inputValues](realitykit/portalmaterial/program-swift.struct/descriptor-swift.struct/inputvalues.md)