---
title: "Dirt"
url: "https://help.maxon.net/c4d/en-us/Content/html/XBRICK-BRICK_GROUP_DIRT.html"
section_path: "Material Manager > Classic Materials > Classic material > Channel Shaders > Brick > Dirt"
element_id: "XBRICK"
group_id: "BRICK_GROUP_DIRT"
description: "Enabling this option lets you lay a layer of dirt over the bricks."
---

## Dirt

### Enable

Parameter ID: `BRICK_DIRT_ENABLE`

Enabling this option lets you lay a layer of dirt over the bricks.

### Brick

Parameter ID: `BRICK_DIRT_ENABLE_BRICK`

### Gap

Parameter ID: `BRICK_DIRT_ENABLE_GAP`

Here you can define if dirt should be applied to bricks and / or mortar, respectively.

### Opacity

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

Defines the degree of dirtiness. 0% results in no dirt being visible, 100% produces maximum visibility.

### Gap Blending

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

### Brick Blending

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

These values define how the dirt colors will be blended with the brick or mortar color:

- 0%: colors will simply be blended
- Positive values up to 100%: a negative multiply blend mode will be used; produces brighter, dustier dirt.
- Negative values up to -100%: a dodge-and-burn blend mode will be used; produces darker, more oily dirt.

### Color

Parameter ID: `BRICK_DIRT_COL`

A dirt color will be created using this gradient.

### Color Scale

Parameter ID: `BRICK_DIRT_COL_SCALE` · Range: [-∞..+∞%]

Defines the size of the internal Noise that in turn controls the color extraction from the gradient.

### Shift

Parameter ID: `BRICK_DIRT_ALPHA_SHIFT` · Range: [XYZ %]

Shifts the dirt in X and Y directions. **Z** varies the Noise and therewith the dispersion of dirt.

### Opacity Scale

Parameter ID: `BRICK_DIRT_ALPHA_SCALE` · Range: [-∞..+∞%]

Defines the scale of the internal Noise that defines how fine the dirt is. Smaller values result in a more homogenous dispersion of dirt and larger values will produce more variation.

### Octaves

Parameter ID: `BRICK_DIRT_ALPHA_OCT` · Range: [0.00..10.00]

Defines the "muteness" or turbulence of the noise.

### Texture

Parameter ID: `BRICK_DIRTTEX_LINK`

![Image: 031412.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/031412.jpg)\
Dirt textures can produce a more realistic look.

Load a texture here that will be used instead of Noise. An alpha channel will be calculated internally from this texture (in consideration of both **Alpha** parameters) and combined with the texture.

If you load a cement texture here you can achieve a very nice realistic dirt effect on the brick wall.

### Color Texture

Parameter ID: `BRICK_DIRTTEX_COLOR_LINK`

![Image: 031413.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/031413.jpg)\
The Color Texture is well-suited for creating billboards or graffiti.

Here you can load an additional texture that appears at the location defined by the **Texture** setting's alpha channel. This can be very useful for creating very weathered or washed out posters stuck on walls or graffiti.

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

### Shift

Parameter ID: `BRICK_DIRTTEX_SHIFT` · Range: [XYZ %]

Use this setting to move the Texture/Color Texture in X, Y or Z directions (the latter only for 3D shaders).

### Scale

Parameter ID: `BRICK_DIRTTEX_SCALE` · Range: [-∞..+∞%]

Use this setting to enlarge/reduce the size of your Texture/Color Texture. Values of less than 100% will result in tiling.

### Flip

Parameter ID: `BRICK_DIRTTEX_FLIP`

If enabled, the texture will be rotated clockwise 90°.

### Multiply with Gradient

Parameter ID: `BRICK_DIRTTEX_MULTIPLYCOLOR`

As the name says, the Texture/Color Texture will be multiplied with the Gradient Color.

### Alpha Invert

Parameter ID: `BRICK_DIRTTEX_ALPHA_INVERT`

Inverts the alpha channel (created from the **Texture**). Visible regions will be made transparent and vice-versa.

### Alpha Contrast

Parameter ID: `BRICK_DIRTTEX_ALPHA_CONTRAST` · Range: [0..+∞%]

Changes the contrast of the loaded **Texture**, which results in softer or harder transitions in border regions between dirt textures and bricks.

### Alpha Bias

Parameter ID: `BRICK_DIRTTEX_ALPHA_BIAS` · Range: [-∞..+∞%]

This value defines the degree of expansion of the alpha channel (created from the **Texture**). You can quasi let the dirt expand – let it spread across the surface.

### Rain

Parameter ID: `BRICK_DIRTTEX_RAIN` · Range: [0..5000%]

### Samples

Parameter ID: `BRICK_DIRTTEX_RAIN_SAMPLES` · Range: [6..2147483647]

![Image: 031414.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/031414.jpg)\
Left without, right with Rain.

The Rain effect lets you, well, rain on your wall (in the V direction for 2D textures; in the Y direction for 3D shaders). This looks best when applied in conjunction **Texture** at a high contrast setting.

![Image: 031415.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/031415.jpg)\
The dirt texture at left is modified using various **Rain** and **Samples** values.

A **Rain** value of 0% will result in a dry day. Higher values will wet the wall correspondingly, i.e., it will be blurred vertically and will bleach. **Samples** on the other hand will render softer the higher the values defined. Lesser **Sample** values can also produce nice results. The wall will not necessarily look washed out wall but it will look like the dirt has been spread more across the surface – but still sharp and structured.

### Blur Color Texture

Parameter ID: `BRICK_DIRTTEX_RAIN_DOCOLOR`

If a texture is loaded into **Color Texture** that appears at the location defined by **Texture**, the color texture itself can also be washed out (not only its edges).