---
title: sourceAlphaBlendFactor
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtl4renderpipelinecolorattachmentdescriptor/sourcealphablendfactor
---

# sourceAlphaBlendFactor

Configures the source-alpha blend factor.

## Declaration

```swift
var sourceAlphaBlendFactor: MTLBlendFactor { get set }
```

## Discussion

Discussion This property defaults to MTLBlendFactorOne.