---
title: motionStartTime
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtlaccelerationstructuremotioninstancedescriptor/motionstarttime
---

# motionStartTime

A starting time for the range of motion that the key-frame data represents.

## Declaration

```swift
var motionStartTime: Float
```

## Discussion

Discussion The motionTransformsStartIndex and motionTransformsCount properties represent the key-frame motion data. The property’s default value is 0.0.

## See Also

### Specifying motion data

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