---
title: motionStartBorderMode
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtlprimitiveaccelerationstructuredescriptor/motionstartbordermode
---

# motionStartBorderMode

The mode to use when handling timestamps before the start time.

## Declaration

```swift
var motionStartBorderMode: MTLMotionBorderMode { get set }
```

## Discussion

Discussion The default value is MTLMotionBorderMode.clamp.

## See Also

### Specifying motion behavior

- [motionKeyframeCount](metal/mtlprimitiveaccelerationstructuredescriptor/motionkeyframecount.md)
- [motionStartTime](metal/mtlprimitiveaccelerationstructuredescriptor/motionstarttime.md)
- [motionEndTime](metal/mtlprimitiveaccelerationstructuredescriptor/motionendtime.md)
- [motionEndBorderMode](metal/mtlprimitiveaccelerationstructuredescriptor/motionendbordermode.md)
- [MTLMotionBorderMode](metal/mtlmotionbordermode.md)