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Dirt

Cellular Default

The Dirt texture is one of the many procedurally generated textures provided with Modo. Procedural textures are mathematically created at render-time, and therefore have no fixed resolution, they can be magnified nearly infinitely with no visual loss in detail. The Dirt texture can be addressed by its two zones, the Background and Foreground colors. The texture modulates from one zone to the other based on your settings. Each zone can have either a Value or a Color and Alpha. The applied zone is dependent on the Layer Effects to which the texture is applied. For instance, if the texture is applied as a Displacement, the Value settings would be used, whereas setting the texture effect to Diffuse Color would use the Color and Alpha settings for Background and Foreground. This shader provides a way to dirty up objects so they don't look quite so pristine. The dirt function can be applied in different ways, providing a splotchy, dusty look as well as a more even, scattered dirt.

NOTE:  For information regarding adding and working with Shader Tree item layers, see the Shader Tree topic.

Emodo Properties

Option

Description

Layer

Enable

Toggles the effect of the layer on and off, duplicating the functionality of toggling visibility in the Shader Tree. When disabled, the layer has no effect on the shading of the scene. However, disabled layers are saved with the scene and are persistent across Modo sessions.

Invert

Inverts the RGB values for the layer producing a negative effect.

Blend Mode

Affects blending between different layers of the same effect type, allowing you to stack several layers for different effects.

For more on blending, please see the Layer Blend Modes page of the documentation.

Opacity

Changes the transparency of the current layer. Reducing this value increasingly reveals lower layers in the Shader Tree if present, or dim the effect of the layer itself on the surface.

Locator

Most texture layers also have an associated Texture Locator that is automatically created in the Item List. This defines the mapping of the texture, the way it is applied, to the surface. The Locator option sets that association. While you can choose alternate locators, the need to do so is very rare, still, there are some possible instances where you may want multiple texture items to share a single locator.

Organic - Dirt

Noise Type

Specifies the look of the texture distortion, with several noise function types provided:

Perlin

Enhanced Perlin

Gradient

Value

Gradient Value

Impulse

Lattice

Bubble

Noise Seed

The Seed value is the initial number used when generating the procedural values. Different Seed values produce different random variations and can be useful in changing the texture result, however, you need to use the same Seed value when it is necessary for items to retain the same variations.

Frequency 1

Controls the first frequency of the texture. Increasing this value creates more turbulence, stirring up the pattern.

Magnitude 1

Controls the first magnitude of each iteration of the noise. Increasing this value tightens the delineation between the background and foreground color.

Frequency 2

Controls the second frequency of the texture. Increasing this value creates more turbulence, stirring up the pattern.

Magnitude 2

Controls the second magnitude of each iteration of the noise. Increasing this value tightens the delineation between the background and foreground color.

Output Controls

Lower Clip

Specifies a clip level for the Background Color/Value, truncating values beyond the defined setting. Combined with the Upper Clip value, you can apply this option to extend or contract the total range of values for the texture.

Upper Clip

Specifies a clip level for the Foreground Color/Value, truncating values beyond the defined setting. Combined with the Lower Clip value, you can apply this option to extend or contract the total range of values for the texture.

Bias

Increasing this value causes the texture to favor the foreground color over the background color, whereas decreasing the value causes the background color to be favored.

Gain

Similar to a gamma control that affects the falloff of the gradient ramp between the two color values. Setting the Gain to 100% creates a very sharp falloff effect, whereas setting the value to 0% creates a plateau around the value or color mid-point with sharp falloff on either extreme of the gradient.

Output Regions

When the Output Regions option is enabled, the procedural texture outputs random gray shades per region rather than outlines for tiles, providing a means to add random variety to the procedurally created texture. You can further control the amount of variation using the Regional HSV process layer.

Background Color/Value

Specifies the Color (or Value) of the texture's background area, which ramps toward the Foreground Color/Value.

Background Alpha

Specifies the Alpha transparency of the Background Color.

Background - Use Last Layer

When enabled, the Background Color area is completely transparent, revealing the shading results of any lower layers.

Foreground Color/Value

Specifies the Color (or Value) of the texture's foreground area, which ramps toward the Background Color/Value.

Foreground Alpha

Specifies the Alpha transparency of the Foreground Color.

Foreground - Use Last Layer

When enabled, the Foreground Color area is completely transparent, revealing the shading results of any lower layers.