---
title: highDynamicRangeCompression
framework: modelio
role: symbol
role_heading: Instance Property
path: modelio/mdlskycubetexture/highdynamicrangecompression
---

# highDynamicRangeCompression

Two parameters that determine the brightness compression curve for colors in the texture image.

## Declaration

```swift
var highDynamicRangeCompression: vector_float2 { get set }
```

## Discussion

Discussion To render a sky texture, Model I/O first simulates the colors visible in the sky at different directions and then applies tone mapping to fit the resulting colors into the range of displayable values. In tone mapping, Model I/O ignores values below the x component of this vector, clamps color values at or above the y component to the maximum display brightness, and smoothly scales color values in between those points.

## See Also

### Working with Tone Mapping Parameters

- [gamma](modelio/mdlskycubetexture/gamma.md)
- [exposure](modelio/mdlskycubetexture/exposure.md)
- [brightness](modelio/mdlskycubetexture/brightness.md)
- [contrast](modelio/mdlskycubetexture/contrast.md)
- [saturation](modelio/mdlskycubetexture/saturation.md)