---
title: motionTransformsStartIndex
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtlindirectaccelerationstructuremotioninstancedescriptor/motiontransformsstartindex
---

# motionTransformsStartIndex

The index of the first set of transforms describing one keyframe of the animation.

## Declaration

```swift
var motionTransformsStartIndex: UInt32
```

## See Also

### Specifying motion data

- [motionStartTime](metal/mtlindirectaccelerationstructuremotioninstancedescriptor/motionstarttime.md)
- [motionStartBorderMode](metal/mtlindirectaccelerationstructuremotioninstancedescriptor/motionstartbordermode.md)
- [motionEndTime](metal/mtlindirectaccelerationstructuremotioninstancedescriptor/motionendtime.md)
- [motionEndBorderMode](metal/mtlindirectaccelerationstructuremotioninstancedescriptor/motionendbordermode.md)
- [motionTransformsCount](metal/mtlindirectaccelerationstructuremotioninstancedescriptor/motiontransformscount.md)