---
title: MTLTessellationFactorStepFunction.perInstance
framework: metal
role: symbol
role_heading: Case
path: metal/mtltessellationfactorstepfunction/perinstance
---

# MTLTessellationFactorStepFunction.perInstance

A per-instance step function. For a given instance ID, the tessellation factor for a patch in a patch draw call is at the offset + (instanceID * instanceStride) location in the tessellation factor buffer.

## Declaration

```swift
case perInstance
```

## See Also

### Factor step functions

- [MTLTessellationFactorStepFunction.constant](metal/mtltessellationfactorstepfunction/constant.md)
- [MTLTessellationFactorStepFunction.perPatch](metal/mtltessellationfactorstepfunction/perpatch.md)
- [MTLTessellationFactorStepFunction.perPatchAndPerInstance](metal/mtltessellationfactorstepfunction/perpatchandperinstance.md)