FastNoise

Background

FastNoise is the backbone behind Cave Generator's most interesting features. It is what enables the mod to generate complex features using a variety of different settings. Cave Generator uses a lightly modified version of this library to provide even more control over the various shapes it produces.

Previewing your caves

The original creator of FastNoise, @Auburn, has also released a preview application which covers the majority of settings used by Cave Generator. You can find it in the readme on the FastNoise page on GitHub.

Here's a quick peak at how the application looks. It can help you understand your changes more quickly and in smaller increments.

Note

Cave Generator's implementation of FastNoise has recently gone out of date. As a result, a few of the settings are either missing from the preview application or from Cave Generator itself. I will work on implementing the missing features in a later release.

Using FastNoise in Cave Generator

You may have seen a few specialized implementations of these settings on a previous page about noise generation. Cave Generator divides noise settings into two objects, noise2D and noise3D, which represent the two most important use cases noise generation has in the mod: 2-dimensional and 3-dimensional noise generation. We will outline all of the different settings these features have on this page.

2-dimensional noise settings

Technically, noise2D is ambiguous. It can either be used to generate heightmaps or determine placement based on scale. Depending on which it is doing, not all of the settings may be used. I am hoping to change this in a future version, but I need a clear solution which can easily be converted from current presets.

This table outlines all of the settings found in noise2D. Notice that some of the settings are only used when generating heightmaps, one of them is used for placement, and some are used for both.

Field	Type	Default	Use	Description
minVal	integer	-1	heightmaps	The lowest value this generator can produce.
maxVal	integer	1	heightmaps	The highest value this generator can produce.
scale	float	0.5	placement	A value 0 - 1. Produces a threshold for placement.
frequency	float	1.0	both	Waveform frequency of the noise generated.
seed	integer		both	An optional seed used for this generator.

Note

All of these values have defaults, but most objects that use them have overrides to produce better effects. <Todo: link me>

3-dimensional noise settings

This table outlines all of the settings found in noise3D. There is much less ambiguity about what these settings are used for, but there are also a lot of settings.

Field	Type	Default	Description
scale	float	0.5	A value of 0 - 1. Produces a threshold for placement.
frequency	float	1.0	Waveform frequency of the noise generated.
scaleY	float	1.0	Stretches or skews the noise vertically.
lacunarity	float	1.0	Octave lacunarity for fractal noise types.
gain	float	0.5	Octave gain for fractal noise types.
jitter	float	0.45	Cellular point movement for cellular noise types.
jitterX	float	0.45	Overrides jitter on the x-axis.
jitterY	float	0.45	Overrides jitter on the y-axis.
jitterZ	float	0.45	Overrides jitter on the z-axis.
octaves	integer	1	Fractal resolution and number of generation passes.
perturb	boolean	false	Whether to apply a gradient perturb and warp the output.
perturbAmp	float	1.0	Maximum amount to warp the output when using perturb.
perturbFreq	float	0.1	The frequency used by the perturb function.
invert	boolean	false	Whether to completely invert the output of the generator.
type	string	SimplexFractal	The type of noise generation to use.
interp	string	Hermite	The type of interpolation to use.
fractal	string	FBM	The type of fractalization to apply, where applicable.
distFunc	string	Euclidian	The type distance function used with cellular types.
returnType	string	Distance2	The return type from cellular noise types.
cellularLookup	string	Simplex	The type of noise to use when returnType == NoiseLookup.
seed	integer		An optional seed for sharing between generators.

Note

All of these values have defaults, but most objects that use them have overrides to produce better effects. <Todo: link me>

Special types

Here's a list of each special type from FastNoise and Cave Generator along with every possible value it can have. These are not case sensitive.

Noise types

These are the possible values you can write for type and cellularLookup.

• Value
• ValueFractal
• Perlin
• PerlinFractal
• Simplex
• SimplexFractal
• Cellular
• WhiteNoise
• Cubic
• CubicFractal

Interpolation types

These are the possible values you can write for interp.

• Linear
• Hermite
• Quintic

Fractal types

These are the possible values you can write for fractal.

• FBM
• Billow
• RigidMulti

Distance functions

These are the possible values you can write for distFunc.

• Euclidian
• Manhattan
• Natural

Cellular return types

These are the possible values you can write for returnType.

• CellValue
• NoiseLookup
• Distance
• Distance2
• Distance2Add
• Distance2Sub
• Distance2Mul
• Distance2Div
• Distance3
• Distance3Add
• Distance3Sub
• Distance3Mul
• Distance3Div

Continue reading

Continue to presets: decorations