---
title: "Curl"
url: "https://help.maxon.net/c4d/en-us/Content/html/MHAIRMATERIAL-HAIRMATERIAL_GROUP_CURL.html"
section_path: "Simulate Menu > The Simulation System > Hair > Hair material > Hair Material > Curl"
element_id: "MHAIRMATERIAL"
group_id: "HAIRMATERIAL_GROUP_CURL"
description: "The Curl channel curls the hair by slightly rotating each segment of hair."
---

## Curl

The **Curl** channel curls the hair by slightly rotating each segment of hair.

### Curl

Parameter ID: `HAIRMATERIAL_CURL` · Range: [-∞..+∞°]

![Image: 005247.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005247.jpg)\
Increasing **Curl** values from left to right.

**Curl** defines the degree to which the hair should be curled. The higher the value, the curlier the hair will be. A negative value will reverse the direction of the curl.

![Image: 005248.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005248.jpg)\
Negative and positive **Curl** values in comparison.

Of course, such curls can also be created using guide styles in the Hair Tools (e.g., the [Curl Tool](https://help.maxon.net/c4d/en-us/Content/html/TOOLHAIRCURL.html.md)).

### Variation

Parameter ID: `HAIRMATERIAL_CURL_VAR` · Range: [0..100%]

Use the **Variation** setting to adjust the irregularity of the curl.

### Amount

Parameter ID: `HAIRMATERIAL_CURL_AMOUNT` · Range: [0..100%]

Use this slider to define the percentage of hair hat should be affected by **Curl**.

### Direction

Parameter ID: `HAIRMATERIAL_CURL_DIRECTION`

Use this setting to define which coordinate system should affect the hair. You can select from:

World

World coordinate system (direction is determined using the **Axis** setting).

Local

Object coordinate system (direction is determined using the **Axis** setting).

Random

Each hair will curl in a random direction.

Hair

The hair will curl in the direction already defined by guides for the hair curvature and waves.

### Variation

Parameter ID: `HAIRMATERIAL_CURL_DN_VAR` · Range: [-100..100%]

If one of the coordinate systems was selected in the **Direction** setting, **Variation** will randomly vary the axis of rotation for each hair.

### Axis

Parameter ID: `HAIRMATERIAL_CURL_DIRECTION_AXIS`

Use this setting to define around which axis the hair should curl. Use the **Direction** setting to select a coordinate system (world or local).

### Texture

Parameter ID: `HAIRMATERIAL_CURL_DN_SHADER`

If you select **Texture**, the following will apply with regard to RGB values:

- Red: Rotational axis = X
- Green: Rotational axis = Y
- Blue: Rotational axis = Z

Instead of describing complex mathematical vector calculations, we will simply use the images below to demonstrate the effect different colors have on curling hair.

![Image: 005249.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005249.jpg)\
RGB colors and their corresponding rotational axes.

![Image: subgroup.gif](https://help.maxon.net/c4d/en-us/Content/Resources/Images/subgroup.gif)\
Advanced

### Curling

Parameter ID: `HAIRMATERIAL_CURL_CURVE`

Use this function graph to define the strength of curl (**Curl** setting at top) along the entire length of the hair.

![Image: 005250.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005250.jpg)\
Various graphs and their effect on the guides shown at the lower left.

### Texture

Parameter ID: `HAIRMATERIAL_CURL_SHADER`

A texture loaded here will define the strength of curl (**Curl** setting at top) across an entire surface.