---
title: "init(floatLiteral:)"
framework: realitykit
role: symbol
role_heading: Initializer
path: "realitykit/custommaterial/opacity/init(floatliteral:)"
---

# init(floatLiteral:)

Creates an opacity object from a single value.

## Declaration

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

## Parameters

- `value`: The opacity value.

## Discussion

Discussion This initializer creates an object that defines the opacity of an entity using a single value for the entire entity. This value is available to the material’s surface shader function, but RealityKit draws the entity fully opaque unless the surface shader function calls params.surface().set_opacity(). The following Metal code demonstrates how to set the entity’s opacity in the material’s surface shader function based on value:     // Retrieve the opacity scale from the CustomMaterial.     float opacityScale = params.material_constants().opacity_scale();

// Use the opacity scale to set the current pixel's opacity.     params.surface().set_opacity(opacityScale);

## See Also

### Creating an opacity object

- [init(scale:texture:)](realitykit/custommaterial/opacity/init(scale:texture:).md)
- [init(_:)](realitykit/custommaterial/opacity/init(_:).md)