From BlenderWiki

Procedural Textures

Description

Procedural textures are textures that are defined mathematically. They are generally relatively simple to use, because they don't need to be mapped in a special way - which doesn't mean that procedural textures can't become very complex.

These types of textures are 'real' 3D. By that we mean that they fit together perfectly at the edges and continue to look like what they are meant to look like even when they are cut; as if a block of wood had really been cut in two. Procedural textures are not filtered or anti-aliased. This is hardly ever a problem: the user can easily keep the specified frequencies within acceptable limits.

Options

The non procedural textures are greyed out in The Texture Type list.

Nabla

Almost all procedural textures in Blender use derivatives for calculating normals for texture mapping (with as exception Blend and Magic). This is important for Normal and Displacment Maps. The strength of the effect is controlled with the Nabla Number Button.

Hints

• Use the size buttons in the Map Input Panel to set the size that Procedural Textures are mapped to.

• Procedural textures can either produce colored textures, intensity only textures, textures with alpha values and normal textures. If intensity only ones are used the result is a black and white texture, which can be greately enhanced by the use of colorbands. If on the other hand you use colorbands and need an intensity value, you have to switch on No RGB in the Map To panel.

Noise Basis

Description

Each noise-based Blender texture (with the exception of Voronoi and simple noise) has a Noise Basis setting that allows the user to select which algorithm is used to generate the texture. This list includes the original Blender noise algorithm. The Noise Basis settings makes the procedural textures extremely flexible (especially Musgrave).

Examples

The Noise Basis governs the structural appearance of the texture.

Cellnoise	Voronoi Crackle	Voronoi F2-F1
Voronoi F4	Voronoi F3	Voronoi F2
Voronoi F1	Blender Original

There are two more possible settings for Noise Basis, which are relatively similar to Blender Original:

• Improved Perlin
• Original Perlin

Clouds

Description

Often used for: Clouds, Fire, Smoke. Well suited to be used as Bumpmap, giving an overall irregularity to the material.

Result(s): Intensity (Default) or RGB-Color (Color)

Options

Default

The standard Noise, gives an Intensity.

Color

The Noise gives an RGB value.

Soft Noise/Hard Noise

Changes the contrast and sharpness

NoiseSize

The dimension of the Noise table.

NoiseDepth

The depth of the Cloud calculation. A higher number results in a long calculation time, but also in finer details.

Examples

Technical Details

A three-dimensional table with pseudo random values is used, from which a fluent interpolation value can be calculated with each 3D coordinate (thanks to Ken Perlin for his masterful article "An Image Synthesizer", from the SIGGRAPH proceedings 1985). This calculation method is also called Perlin Noise. In addition, each noise-based Blender texture (with the exception of Voronoi and simple noise) has a new "Noise Basis" setting that allows the user to select which algorithm is used to generate the texture.

Marble

Description

Often used for: Marble, Fire, Noise with a structure.

Result(s): Intensity value only.

Options

Soft/Sharp/Sharper

Three pre-sets for soft to more clearly defined Marble.

Soft Noise/Hard Noise

The Noise function works with two methods.

NoiseSize

The dimensions of the Noise table.

NoiseDepth

The depth of the Marble calculation. A higher value results in greater calculation time, but also in finer details.

Turbulence

The turbulence of the sine bands.

Examples

Technical Details

Bands are generated based on a sine formula and Noise turbulence.

Stucci

Description

Often used for: Stone, Asphalt, Oranges. Normally for Bump-Mapping to create grainy surfaces.

Result(s): Normals and Intensity

Options

Plastic

The standard Stucci.

Wall In, Wall out

This is where Stucci gets it name. This is a typical wall structure with holes or bumps.

Soft Noise/Hard Noise

There are two methods available for working with Noise.

NoiseSize

The dimension of the Noise table.

Turbulence

The depth of the Stucci calculations.

Examples

Technical Details

Based on noise functions

Wood

Description

Often used for: Wood

Result(s): Intensity only

Options

Bands

The standard Wood texture.

Literal|Rings

This suggests 'wood' rings.

BandNoise

Gives the standard Wood texture a certain degree of turbulence.

RingNoise

Gives the rings a certain degree of turbulence.

Soft Noise/Hard Noise

There are two methods available for the Noise function.

NoiseSize

The dimension of the Noise table.

Turbulence

The turbulence of the BandNoise and RingNoise types.

Examples

See the section Doc:Tutorials/Textures/Wood for a method to create procedural wood.

Colorbands are used in both materials and textures, as well as other places where a range of colors can be computed and dipslayed. In the example to the right, we want to texture a snake, specifically the deadly coral snake. We want to make a repeating set of four colors: Black, yellow, red, yellow (and then back to black again). We also want to make the rings sharp in definition and transition. This example uses 8 color band settings: 0 and 7 are black; 1 and 2 are yellow, 3 and 4 are red, and 5 & 6 are yellow. Position 0 and 1 close together, 2 and 3, etc. Use a little noise and turbulence; together with the scales texture you should get really close!

Technical Details

Generation

In this case, bands are generated based on a sine formula. You can also add a degree of turbulence with the Noise formula.

Coordinates

As the band is based on a sine formula, the texture repeats itself every pi units rather than every 1.0 units. To correct this, scale the texture by a value of pi for the dimension you wish.

Magic

Description

Often used for: This is difficult, it was hard to find an application whatsoever. One could use it for "Thin Film Interference", if you set Map Input to Refl and use a relatively high Turbulence.

Result(s): RGB

Options

Depth

The depth of the calculation. A higher number results in a long calculation time, but also in finer details.

Turbulence

The strength of the pattern.

Examples

I've used two Magic Textures in "Thin Film Interference" with Magic Texture. Both use the same texture with Depth 4, Turbulance 12. Both have Map Input set to Refl. The first texture is mapped to Nor, the second to Col.

Technical Details

The RGB components are generated independently with a sine formula.

Blend

Description

Often used for: This is one of the most important procedural textures. You can use blend textures to blend other textures together (with Stencil), or to create nice effects (especially with the Map Input: Nor trick). Just remember: if you use a colorband to create a custom blending, you may have to use No RGB, if the Map To value needs an intensity input!

Result(s): Intensity

Options

Lin

A linear progression.

Quad

A quadratic progression.

Ease

A flowing, non-linear progression.

Diag

A diagonal progression.

Sphere

A progression with the shape of a three-dimensional ball.

Halo

A quadratic progression with the shape of a three-dimensional ball.

Flip XY

The direction of the progression is flipped a quarter turn.

Examples

Technical Details

The Blend texture generates a smoothly interpolated progression.

Noise

Description

Often used for: White noise in an animation. This is not well suited if you don't want an animation. For material roughness take clouds instead.

Result(s): Intensity

Options

There is no panel and no buttons. Just switch it on.

Technical Details

Although this looks great, it is not Perlin Noise! This is a true, randomly generated Noise. This gives a different result every time, for every frame, for every pixel.

Musgrave

Description

Often used for: Organic materials, but it's very flexible. You can do nearly everything with it.

Result(s): Intensity

Options

Noise Types

This procedural texture has five noise types on which the resulting pattern can be based and they are selectable from a dropdown menu at the top of the tab. The five types are:

• fBm:
• Hetero Terrain:
• Hybrid Multifractal:
• Ridged Multifractal:
• Multifractal:

These noise types determine the manner in which Blender layers successive copies of the same pattern on top of each other at varying contrasts and scales.

In addition to the five noise types, Musgrave has a noise basis setting which determines the algorithm that generates the noise itself. These are the same noise basis options found in the other procedural textures.

The main noise types have four characteristics which can be set in the number buttons below the dropdown list. They are:

H (Fractal Dimension) - Range 0 to 2)

Fractal dimension controls the contrast of a layer relative to the previous layer in the texture. The higher the fractal dimension, the higher the contrast between each layer, and thus the more detail shows in the texture.

Lacu (Lacuniarity) - Range 0 to 6)

Lacuniarity controls the scaling of each layer of the Musgrave texture, meaning that each additional layer will have a scale that is the inverse of the value which shows on the button. i.e. Lacu = 2 -> Scale = 1/2 original

Octs (Octave) - Range 0 to 8)

Octave controls the number of times the original noise pattern is overlayed on itself and scaled/contrasted with the fractal dimension and lacuniarity settings.

The Hybrid Multifractal, Ridged Multifractal, and Hetero Terrain types have additional settings:

Ofst (Fractal Offset)

All three have a "Fractal Offset" button labeled Ofst. This serves as a "sea level" adjustment and indicates the base height of the resulting bump map. Bump values below this threshold will be returned as zero.

Gain

Hybrid Multifractal and Ridged Multifractal both have a Gain setting which determines the range of values created by the function. The higher the number, the greater the range. This is a fast way to bring out additional details in a texture where extremes are normally clipped off.

Examples

See the Samples Gallery from the release notes for more examples.

Leather made with a single Musgrave Texture

Stone made with a combination of 3 different Musgrave Textures.

Technical Details

More information about these textures can be found at the following URL: Musgrave Documentation

Voronoi

Description

Often used for: Very convincing Metal, especially the "Hammered" effect. Organic shaders (e.g. scales, veins in skin).

Result(s): Intensity (default), Color.

Options

Distance Metric

This procedural texture has seven Distance Metric options. These determine the algorithm to find the distance between cells of the texture. These options are:

• Minkovsky
• Minkovsky 4
• Minkovsky 1/2
• Chebychev
• Manhattan
• Distance Squared
• Actual Distance

The Minkovsky setting has a user definable value (the Exp button) which determines the exponent (e) of the distance function (xe + ye + ze)1/e. A value of one produces the Manhattan distance metric, a value less than one produces stars (at 0.5, it gives a Minkovsky 1/2), and higher values produce square cells (at 4.0, it gives a Minkovsky 4, at 10.0, a Chebychev). So nearly all Distance Settings are basically the same - variations of Minkowsky.

You can get irregularly-shaped rounded cells with the Actual Distance/Distance Squared options.

Four sliders at the bottom of the Voronoi panel represent the values of the four Worley constants (explained a bit in the Worley Documentation), which are used to calculate the distances between each cell in the texture based on the distance metric. Adjusting these values can have some interesting effects on the end result. Check the Samples Gallery for some examples of these settings and what textures they produce.

At the top of the panel there are four variation buttons which use four different noise basis as methods to calculate color and intensity of the texture output. This gives the Voronoi texture you create with the "Worley Sliders" a completely different appearance and is the equivalent of the noise basis setting found on the other textures.

Examples

See the Samples Gallery from the release notes for more examples.

Manhattan

Cebychev

Minkowsky 10

Noise Basis Int.

Noise Basis Col1.

Noise Basis Col2.

Noise Basis Col3.

Technical Details

For a more in depth description of the Worley algorithm, see: Worley Documentation.

Distorted Noise

Description

Often used for: Grunge, very complex and versatile

Result(s): Intensity

Options

Distortion Noise

The texture to use to distort another

Noise Basis

The texture to be distorted

Noise Size

The size of the noise generated

Distortion Amount

The amount that Distortion Noise affects Noise Basis

Examples

See the Samples Gallery from the release notes for more examples.

Technical Details

Distortion Noise takes the option that you pick from Noise Basis and filters it, to create hybrid pattern.