---
title: "generatingNormalMap(withSmoothness:contrast:)"
framework: spritekit
role: symbol
role_heading: Instance Method
path: "spritekit/sktexture/generatingnormalmap(withsmoothness:contrast:)"
---

# generatingNormalMap(withSmoothness:contrast:)

Creates a normal map texture by analyzing the contents of an existing texture.

## Declaration

```swift
func generatingNormalMap(withSmoothness smoothness: CGFloat, contrast: CGFloat) -> Self
```

## Parameters

- `smoothness`: A number between 0.0 and 1.0 indicating how much the texture should be smoothed before the normal map is generated. A value of 0.0 means that the texture is not smoothed at all before being processed.
- `contrast`: A value used to magnify the effect of the generated normal map. A value of 1.0 indicates no magnification is applied.

## Return Value

Return Value A new texture object that contains a normal map.

## Discussion

Discussion A normal map texture is similar to an image texture, but instead of holding image data to be displayed onscreen, every texel represents a normal vector. Normal map textures are used to simulate 3D lighting (see the normalTexture property) or used to generate velocity values (see velocityField(with:)). You can create normal maps in two different ways. First, you can take an existing image map and use it to generate a normal map. SpriteKit filters the color data in the texture and then uses it to generate a map based on pixel contrast. Alternatively, you can load a regular image file but treat it as a normal map. To do this, provide a texture with 32-bit RGBx pixel data. Each component’s 8-bit integer value is mapped to a floating point number between the values of -1.0 and 1.0. Use a 0 to represent -1.0f, a value of 127 to represent 0.0, and a value of 255 to represent +1.0. The image below shows two sprite nodes both with the same texture. The node on the right has a normal map from the same noise texture generated using the generatingNormalMap() method.

## See Also

### Texture from Normal Map

- [generatingNormalMap()](spritekit/sktexture/generatingnormalmap().md)