---
title: normal
framework: modelio
role: symbol
role_heading: Instance Property
path: modelio/mdlscatteringfunction/normal
---

# normal

The variation in the surface normal vectors in a material, relative to model coordinate space.

## Declaration

```swift
var normal: MDLMaterialProperty { get }
```

## Discussion

Discussion The default normal value is zero (no variation in surface normal vectors). Typically, you assign a texture to this material property to create the appearance of detailed surface contours.

## See Also

### Working with Shading Properties

- [baseColor](modelio/mdlscatteringfunction/basecolor.md)
- [emission](modelio/mdlscatteringfunction/emission.md)
- [specular](modelio/mdlscatteringfunction/specular.md)
- [materialIndexOfRefraction](modelio/mdlscatteringfunction/materialindexofrefraction.md)
- [interfaceIndexOfRefraction](modelio/mdlscatteringfunction/interfaceindexofrefraction.md)
- [ambientOcclusion](modelio/mdlscatteringfunction/ambientocclusion.md)
- [ambientOcclusionScale](modelio/mdlscatteringfunction/ambientocclusionscale.md)