---
title: MTLStepFunction.constant
framework: metal
role: symbol
role_heading: Case
path: metal/mtlstepfunction/constant
---

# MTLStepFunction.constant

The function fetches attribute data once.

## Declaration

```swift
case constant
```

## See Also

### Step options

- [MTLStepFunction.perInstance](metal/mtlstepfunction/perinstance.md)
- [MTLStepFunction.perPatch](metal/mtlstepfunction/perpatch.md)
- [MTLStepFunction.perPatchControlPoint](metal/mtlstepfunction/perpatchcontrolpoint.md)
- [MTLStepFunction.perVertex](metal/mtlstepfunction/pervertex.md)
- [MTLStepFunction.threadPositionInGridX](metal/mtlstepfunction/threadpositioningridx.md)
- [MTLStepFunction.threadPositionInGridY](metal/mtlstepfunction/threadpositioningridy.md)
- [MTLStepFunction.threadPositionInGridXIndexed](metal/mtlstepfunction/threadpositioningridxindexed.md)
- [MTLStepFunction.threadPositionInGridYIndexed](metal/mtlstepfunction/threadpositioningridyindexed.md)