---
title: buildScratchBufferSize
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtlaccelerationstructuresizes/buildscratchbuffersize
---

# buildScratchBufferSize

The amount of scratch memory, in bytes, the GPU devices needs to build the acceleration structure.

## Declaration

```swift
var buildScratchBufferSize: Int
```

## See Also

### Retrieving the sizes

- [accelerationStructureSize](metal/mtlaccelerationstructuresizes/accelerationstructuresize.md)
- [refitScratchBufferSize](metal/mtlaccelerationstructuresizes/refitscratchbuffersize.md)