pseudofractals-voxel-shader

Voxel shader (for MagicaVoxel) to generate pseudofractal volumes.

Installing and updating

Copy the files in shaders/ to the shader/ folder in your installation of MagicaVoxel.

Usage

In MagicaVoxel, execute xs pseudofractal 1.0 1.0 1.0 1.01 26. 0.4 0 in its console.

Parameters

xs pseudofractal xscale yscale zscale distOrder seed threshold cleaning

• xscale : The scale on the X axis. Small number stretches the axis, large number condenses it.
• yscale : The scale on the Y axis. Small number stretches the axis, large number condenses it.
• zscale : The scale on the Z axis. Small number stretches the axis, large number condenses it.
• distOrder : The algorithm uses Minkowski distance which is a generalization of Euclidean and Manhattan distance. This parameter control the "order" of the distance. Values larger than 2 tend to result in squarish structure with flat surfaces. Values very close to 1 (i.e. 1.001) tend to result in regular octahedra. Recommended values are between 0.5 and 2.5.
• seed : The "magic" value used to generate the pseudofractal. To be specific it is used as a modulus. A value of 0 will always result in an empty volume.
• threshold : Controls the ratio of live (solid) voxels. A value of 0 means that all voxels are considered as dead. A value of 1 means that all voxels are considered as alive.
• cleaning : If set and above 0, single / isolated voxels will be removed from the resulting volume.

Recommended workflow

• Start with the *scale set to 1, distOrder set to 2. or 1.001, seed set to a number other than 1 and 0 and threshold set to 0.5.
• Tweak the *scale, distOrder and seed until you have an interesting volume.
• Fine tune the threshold and eventually enable cleaning if there too many isolated voxels.
• For best result, render in MagicaVoxel with marching cubes.

Variants

Included are two variants of the shader.

pseudofractal-sub allows to carve an existing volume with the negative space of the pseudofractal.

pseudofractal-add allows to add the pseudofractal to an existing volume without affecting any of its own voxels.

Both variants use the same parameters as the main shader.

Examples

• https://twitter.com/kchplr/status/1042853519244636160
• https://twitter.com/kchplr/status/1043258155118014464
• https://twitter.com/ephtracy/status/1044071076379185152
• https://twitter.com/ephtracy/status/1044087775526604801
• https://twitter.com/NNNenov/status/1044068357367058432
• https://twitter.com/Omegafoxxx/status/1043324264529649664

xs pseudofractal 1.0 1.0 1.0 1.0 0.7 0.4 1

xs pseudofractal 1.10 1.10 1.10 1.00001 0.1 0.5 1

xs pseudofractal .25 .25 .25 1.33 1.91 0.55 1

xs pseudofractal .5 .5 .5 1.995 0.751 0.55 1

xs pseudofractal 1.5 1.5 0.5 2.0 0.179929 0.5 1

Additional notes

• Thank to Alien who first introduced me to pseudofractals ;)
• Check Jes Wolfe's talk on the subject (youtube) if you want to learn more about pseudofractals.
• If you're interested in this kind of structure generation but want something more predictable and less random, please check cellular-automata-voxel-shader.

History

1.2.0 (2020-06-20) :

• Add experimental brush shader for the new voxel brush feature in MagicaVoxel (0.99.5.1).

1.1.0 (2018-10-05) :

• Add sub and add variants.
• Add examples in doc.

1.0.1 (2018-09-19) :

• Fixed an issue which would make the shader fail to work properly on some GPU.

1.0.0 (2018-09-18) :

• First implementation.