---
title: "init(screenSize:layers:label:)"
framework: metal
role: symbol
role_heading: Initializer
path: "metal/mtlrasterizationratemapdescriptor/init(screensize:layers:label:)"
---

# init(screenSize:layers:label:)

A convenience initializer that creates a rate map descriptor with a set of layer descriptors.

## Declaration

```swift
convenience init(screenSize: MTLSize, layers: [MTLRasterizationRateLayerDescriptor], label: String? = nil)
```

## Parameters

- `screenSize`: The logical size, in pixels, of the viewport coordinate system.
- `layers`: An array of rate layer descriptors for the rate map’s layers.
- `label`: A string that identifies the resulting rate map.

## Return Value

Return Value A descriptor object whose screenSize and label properties are set to the provided values and whose rate map layers are set to the array you provided.

## See Also

### Creating rate map descriptors

- [init(screenSize:label:)](metal/mtlrasterizationratemapdescriptor/init(screensize:label:).md)
- [init(screenSize:layer:label:)](metal/mtlrasterizationratemapdescriptor/init(screensize:layer:label:).md)