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Technical paper:
Semi-Procedural Textures Using Point Process Texture Basis Functions
P. Guehl , R. AllEgre , J.-M. Dischler, B. Benes , and E. Galin
Computer Graphics Forum (EGSR 2020 special issue)
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PPTBF file format
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A PPTBF file store parameters of our PPTBF model (Point Process Texture Basis Functions) of procedural stochastic structures.

Example:

0.892735
5 1 55 0.359 0.850971 0.034 0.872 0.547 1 10 0 2 0 0.812 0.01 0 2 0 5 1 1 0.855 0.855 1 1 0.0844974 1 0

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-------------------- 1st line --------------------
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The first line contains the threshold to apply to the PPTBF procedural model.
This threshold HAS TO be applied after a "histogram egalization" of the PPTBF values to renormalize its values in [0;1]
So, threshold value lies in [0;1.0]

- [0] PPTBF threshold value

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-------------------- 2nd line --------------------
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The second line contains the concatenated list of PPTBF procedural parameters.
They describe 5 types of PPTBF parameters :
- code PPTBF model: point process, window function and feature function.
- additional parameters: transformations and deformations

NOTE: Below, in "values", you will find some values we used in our GUI (graphical user inrterface). Some could be changed, such as minNbKernels and maxNbKernels if you want more kernels to add in your feature function.

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---- Point process ----
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Point set parameters:

- [0] tiling type               : tiling type (e.g., regular, irregular...) - values: {0, 17}
- [1] jittering                 : randomness - values: [0, 1]

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---- Transformation ----
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NOTE: also used for normalization parameters during parameter estimation.

- [2] resolution                : uniform scale (zoom/unzoom) - values: {1, 1000}
- [3] rotation                  : rotation around world coordinate frame at origin (0.0;0.0) - values: [0, 2]
- [4] aspect ratio              : shear on X axis (scale) - values: [0.01, 10]

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---- Turbulence ----
--------------------

Brownian distorsion parameters:

- [5] distorsion base amplitude : - values: [0, 0.25]
- [6] distorsion amplitude gain : - values: [0, 4]
- [7] distorsion frequency      : - values: [0, 1]

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---- Window function ----
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Window function parameters:

- [8] window shape              : window function type - values: {0, 3}
- [9] window arity              : number of control points for smoothing - values: [2, 10]
- [10] window larp              : anisotropy of cellular basis window - values: [0, 1]
- [11] window norm              : cellular basis window norm - values: [0, 3]
- [12] window smoothness        : degree of smoothing - values: [0, 2]
- [13] window blend             : linear combination of the two basis windows - values: [0, 1]
- [14] window sigwcell          : sigma of window - values: [0.01, 4]

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---- Feature function ----
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Feature function parameters:

- [15] feature bombing          : mixture model - values: {0, 4}
- [16] feature norm             : feature norm - values: [0, 3]
- [17] feature winfeatcorrel    : correlation with centroids - values: [0, 1]
- [18] feature aniso            : anisotropy - values: [0, 5]
- [19] feature minNbKernels     : min number of kernels - values: {0, 8}
- [20] feature maxNbKernels     : max number of kernels - values: {0, 8}
- [21] feature sigcos           : sigma of Gabor kernel - values: [0, 10]
- [22] feature sigcosvar        : random variation of [21] (sigma of Gabor kernel) - values: [0, 1]
- [23] feature frequency        : frequency of stringed Gabor stripes - values: {0, 16}
- [24] feature phaseShift       : - values: [0, 1]
- [25] feature thickness        : thickness of stringed Gabor stripes - values: [0.001, 1]
- [26] feature curvature        : curvature of stringed Gabor stripes - values: [0, 1]
- [27] feature orientation      : orientation of stringed Gabor stripes - values: [0, 0.5]