---
title: layerInstructions
framework: avfoundation
role: symbol
role_heading: Instance Property
path: avfoundation/avmutablevideocompositioninstruction/layerinstructions
---

# layerInstructions

Instructions that specify how to layer and compose video frames from source tracks.

## Declaration

```swift
var layerInstructions: [AVVideoCompositionLayerInstruction] { get set }
```

## Discussion

Discussion Tracks are layered in the composition according to the top-to-bottom order of the layerInstructions array; the track with trackID of the first instruction in the array will be layered on top, with the track with the trackID of the second instruction immediately underneath, and so on. If the property value is nil, the output is a fill of the background color.

## See Also

### Configuring the instructions

- [backgroundColor](avfoundation/avmutablevideocompositioninstruction/backgroundcolor.md)
- [timeRange](avfoundation/avmutablevideocompositioninstruction/timerange.md)
- [enablePostProcessing](avfoundation/avmutablevideocompositioninstruction/enablepostprocessing.md)