bluenoise-raytracer/targetrdf

This directory contains the source code for the paper

D. Heck and T. Schloemer and O. Deussen, "Blue Noise Sampling with Controlled Aliasing", ACM Trans. Graph., 2013, in press

If you have questions about the paper or the included source code, please email

Daniel Heck <dheck@gmx.de>

The main program is called "targetrdf", and it attempts to construct a point set matching a given "target RDF" (or a given target spectrum). As a simple example, here is how to generate a step blue noise point set, as presented in the paper:

./targetrdf --steprp --crit 0.606 --out step.txt

--steprp

    Chooses a radial power spectrum with a step characteristic

--crit 0.606

    Sets the position of the step; 0.606 is the numerical value for v_max,
    the maximal realizable step position

--out step.txt

    Writes the final point set to 'step.txt'

There are many additional parameters that can be used to influence the optimization process. A full list is shown by "targetrdf --help".

--npts n --seed s

    Specifies the number of points to use. The points are initialized to
    random positions, and the seed for the RNG can be set to different
    values to generate a family of similar point sets.

--in file

    Load initial point set from 'file'

--reference file

    Loads a point set from 'file' and tries to construct a new point set
    with the same RDF.

--rdf file --spectrum file --rp-as-rdf file

    Loads an RDF or power spectrum from 'file' and tries to construct a
    matching point set. 'rp-as-rdf' can be used to generate "dual" point
    sets by reinterpreting a power spectrum as an RDF.

--peakrp --peak power --peaksmooth sigma --crit

    These paramters are used to generate the single-peak blue noise point
    sets discussed in the paper.

--nbins n --smoothing sigma

    Specifies the number of bins and the amount of smoothing to use when
    calculating RDFs.

FILE FORMATS

The default file formats used by 'targetrdf' are very simple.

Point sets:

• the first line contains the number of points

• the remaining lines contain the x/y coordinates of the points in the unit square

  4096
  0.162776 0.74937
  0.0798951 0.880201
  0.58569 0.782718
  0.697048 0.380065
  0.883548 0.747492
  0.432829 0.344747
  ...
  

RDF/Power spectrum:

• the file contains ordinate/abscissa pairs:

  6.10352e-05 0.00088529
  0.000183105 0.00107669
  0.000305176 0.00145942
  ...
  0.499695 1.0007
  0.499817 1.00067
  0.499939 1.00064
  

• it is assumed that ordinate spacing is uniform