---
title: "init(floatLiteral:)"
framework: realitykit
role: symbol
role_heading: Initializer
path: "realitykit/custommaterial/metallic-swift.struct/init(floatliteral:)"
---

# init(floatLiteral:)

Creates an object from a single value.

## Declaration

```swift
init(floatLiteral value: Float)
```

## Parameters

- `value`: The reflectiveness value for the material.

## Discussion

Discussion In physically based rendering, the metallic property represents the reflectiveness of an entity. This initializer creates a new object that passes a single metallic value to your custom shader functions but doesn’t pass a texture. The following Swift code shows how to specify reflectiveness using a single value for the entire entity: material.roughness = PhysicallyBasedMaterial.Roughness(floatLiteral: 0.0) To render an entity with reflectiveness, set lightingModel to CustomMaterial.LightingModel.lit or CustomMaterial.LightingModel.clearcoat, and call params.surface().set_metallic() from its surface shader. The following Metal code shows how to retrieve the value set in this initializer in your surface shader and use it:     // Retrieve the metallic scale from the CustomMaterial.     float metallic = params.material_constants().metallic_scale();

// Set the roughness value using the metallic scale value.     params.surface().set_metallic(metallic); For more information on creating custom materials and writing shader functions, see Modifying RealityKit rendering using custom materials.

## See Also

### Creating a metallic object

- [init(scale:texture:)](realitykit/custommaterial/metallic-swift.struct/init(scale:texture:).md)
- [init(_:)](realitykit/custommaterial/metallic-swift.struct/init(_:).md)