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

# motionStartBorderMode

A behavior that configures how a motion instance handles timestamps before a starting time.

## Declaration

```swift
var motionStartBorderMode: MTLMotionBorderMode
```

## Discussion

Discussion The property’s default value is MTLMotionBorderMode.clamp.

## See Also

### Specifying motion data

- [motionStartTime](metal/mtlaccelerationstructuremotioninstancedescriptor/motionstarttime.md)
- [motionEndTime](metal/mtlaccelerationstructuremotioninstancedescriptor/motionendtime.md)
- [motionEndBorderMode](metal/mtlaccelerationstructuremotioninstancedescriptor/motionendbordermode.md)
- [motionTransformsStartIndex](metal/mtlaccelerationstructuremotioninstancedescriptor/motiontransformsstartindex.md)
- [motionTransformsCount](metal/mtlaccelerationstructuremotioninstancedescriptor/motiontransformscount.md)