---
title: "Thickness"
url: "https://help.maxon.net/c4d/en-us/Content/html/MHAIRMATERIAL-HAIRMATERIAL_GROUP_THICKNESS.html"
section_path: "Simulate Menu > The Simulation System > Hair > Hair material > Hair Material > Thickness"
element_id: "MHAIRMATERIAL"
group_id: "HAIRMATERIAL_GROUP_THICKNESS"
description: "This channel lets you define the thickness of the hair along its shaft. Usually, the narrower the hair, the more realistic it will look when rendered. The …"
---

## Thickness

This channel lets you define the thickness of the hair along its shaft. Usually, the narrower the hair, the more realistic it will look when rendered. The number of hairs rendered will have to be increased accordingly (Hair object: **Hair** Tab), which also increases render times. A good balance between the two will have to be found to achieve the best results.

> **Tip:** Often, hair effects can be better understood if you render just a few, maybe ten, thick hairs (e.g., a value of 20). The effect of changes to individual settings are then more obvious (and render faster) than if you rendered 4000 thin hairs each time you want to see how the changed setting will look.

Thick hairs serve well for such things grass or weeds, or even for simulating fiberglass.

### Root

Parameter ID: `HAIRMATERIAL_THICKNESS_ROOT` · Range: [0..+∞m]

### Tip

Parameter ID: `HAIRMATERIAL_THICKNESS_TIP` · Range: [0..+∞m]

These settings let you set the thickness of the hair root or hair tip. The thickness of the hair along its length will then be interpolated linearly between these two values. You can also use the function graph below to set your own interpolation between the two values.

![Image: 005206.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005206.jpg)\
From left to right: Increasing **Root** and **Tip** values.

Very thick hairs are ideal for creating fiberglass light strands:

![Image: 005207.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005207.jpg)

### Variation

Parameter ID: `HAIRMATERIAL_THICKNESS_VAR` · Range: [0..+∞m]

This setting varies the thickness of the hair root and tip by randomly adding to or subtracting from the values entered for **Root** and **Tip**.

### Curve

Parameter ID: `HAIRMATERIAL_THICKNESS_CURVE`

This function graph lets you define the shape of the hair along its entire length. This does not make much sense when creating normal hair, but can be used to create interesting effects, such as the one shown below:

![Image: 005208.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005208.jpg)\
**Curve** lets you precisely define the shape of the hair.

In the example above, **Root** and **Tip** values were each set to 12m. To create complex shapes as the one above (and have them look good) thicker **Root** and **Tip** values are recommended. Also, the more complex the shape, the more hair segments that will be required (Hair object: Hair tab / Segments) in order for the curve to be able to accurately create the shape.

### Texture

Parameter ID: `HAIRMATERIAL_THICKNESS_SHADER`

![Image: 005209.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/005209.jpg)\
In the example above, a Voronoi shader was used to define the thickness of the hair.

If you want **Thickness** to affect an entire surface using a grayscale texture, simply load your texture here.