raytraverse.sampler

draw

wavelet and associated probability functions.

raytraverse.sampler.draw.get_detail(samps, f1=None, f2=None, f3=None)

raytraverse.sampler.draw.from_pdf(pdf, threshold, lb=0.5, ub=4)

Sampler

class raytraverse.sampler.Sampler(scene, engine=<class 'raytraverse.renderer.rtrace.Rtrace'>, idres=5, fdres=9, accuracy=1.0, srcn=1, stype='generic', srcdef=None, bands=1, engine_args='', nproc=None, **kwargs)

Bases: object

wavelet based sampling class

Parameters

• scene (raytraverse.scene.Scene) – scene class containing geometry and formatter compatible with engine

• engine (type, optional) – should inherit from raytraverse.renderer.Renderer

• idres (int, optional) – initial direction resolution (as log2(res))

• fdres (int, optional) – final directional resolution given as log2(res)

• accuracy (float, optional) – parameter to set threshold at sampling level relative to final level threshold (smaller number will increase sampling, default is 1.0)

• srcn (int, optional) – number of sources return per vector by run

• stype (str, optional) – sampler type (prefixes output files)

• srcdef (str, optional) – path or string with source definition to add to scene

• plotp (bool, optional) – show probability distribution plots at each level (first point only)

• bands (int, optional) – number of spectral bands returned by the engine

• engine_args (str, optional) – command line arguments used to initialize engine

• nproc (int, optional) – number of processors to give to the engine, if None, uses os.cpu_count()

t0 = 0.00390625

coefficients used to set the sampling thresholds

t1 = 0.0625

lb = 0.25

lower and upper bounds for drawing from pdf

ub = 8

engine = None

raytraverse.renderer.Renderer

bands = None

number of spectral bands / channels returned by renderer based on given renderopts (user ensures these agree).

Type

int

scene = None

scene information

Type

raytraverse.scene.Scene

srcn = None

number of sources return per vector by run

Type

int

accuracy = None

accuracy parameter

Type

float

idres = None

initial direction resolution (as log2(res))

Type

int

weights = None

holds weights for self.draw

Type

np.array

stype = None

sampler type

Type

str

property compiledscene

property levels

sampling scheme

Getter

Returns the sampling scheme

Setter

Set the sampling scheme from (ptres, fdres, skres)

Type

np.array

sample(vecf, vecs, outf=None)

generic sample function

Parameters

• vecf (str) – path of file name with sample vectors shape (N, 6) vectors in binary float format

• vecs (np.array) – sample vectors (subclasses can choose which to use)

• outf (str, optional) – if given, append results to file

Returns

lum – array of shape (N,) to update weights

Return type

np.array

_offset(shape, dim)

for modifying jitter behavior of UV direction samples

Parameters

• shape (tuple) – shape of samples to jitter/offset

• dim (int) – number of divisions in square side

sample_to_uv(pdraws, shape)

generate samples vectors from flat draw indices

Parameters

• pdraws (np.array) – flat index positions of samples to generate

• shape (tuple) – shape of level samples

Returns

• si (np.array) – index array of draws matching samps.shape

• vecs (np.array) – sample vectors

_plot_p(p, level, vm, name, suffix='.hdr', fisheye=True)

_plot_vecs(vecs, level, vm, name, suffix='.hdr')

_linear(x, x1, x2)

threshold(idx)

threshold for determining sample count

detailfunc = 'wav3'

filters = {'cross': (<MagicMock name='mock().__truediv__()' id='140680668775760'>, <MagicMock name='mock().__truediv__()' id='140680668069392'>), 'point': (<MagicMock name='mock().__truediv__()' id='140680668240144'>, <MagicMock name='mock()' id='140680663108432'>), 'prewitt': (<MagicMock name='mock().__truediv__()' id='140680669772048'>, <MagicMock name='mock().__truediv__()' id='140680663620624'>), 'sobel': (<MagicMock name='mock().__truediv__()' id='140680670176144'>, <MagicMock name='mock().__truediv__()' id='140680690838032'>), 'sobelswap': (<MagicMock name='mock().__truediv__()' id='140680667011920'>, <MagicMock name='mock().__truediv__()' id='140680670452624'>), 'wav': (<MagicMock name='mock().__truediv__()' id='140680662473104'>, <MagicMock name='mock().__truediv__()' id='140680663382864'>), 'wav3': (<MagicMock name='mock().__rmul__()' id='140680667711248'>, <MagicMock name='mock().__rmul__()' id='140680667419344'>, <MagicMock name='mock().__rmul__()' id='140680665857552'>)}

draw(level)

draw samples based on detail calculated from weights detail is calculated across direction only as it is the most precise dimension

Returns

• pdraws (np.array) – index array of flattened samples chosen to sample at next level

• p (np.array) – computed probabilities

update_weights(si, lum)

update self.weights (which holds values used to calculate pdf)

Parameters

• si (np.array) – multidimensional indices to update

• lum – values to update with

run_callback(vecfs, name, point, posidx, vm)

handle class specific cleanup and lightpointKD construction

_dump_vecs(vecs, vecf)

run(point, posidx, vm=None, plotp=False, log=False, outf=True, **kwargs)

Parameters

• point (np.array) – point to sample

• posidx (int) – position index

• vm (raytraverse.mapper.ViewMapper) – view direction to sample

• plotp – plot weights, detail and vectors for each level

• log – whether to log level sampling rates can be ‘scene’, ‘err’ or None ‘scene’ - logs to Scene log file ‘err’ - logs to stderr anything else - does not log incremental progress

• outf (bool, optional) – some inheriting classes do not need an outfile, but this should not be changed unless the class stores the lum results directly and the run_callback of the class does not expect the file to exist.

SkySampler

class raytraverse.sampler.SkySampler(scene, engine=<class 'raytraverse.renderer.rcontrib.Rcontrib'>, skyres=10.0, engine_args='-ab 7 -ad 2 -c 16200 -as 0 -lw .0625', **kwargs)

Bases: raytraverse.sampler.sampler.Sampler

sample contributions from the sky hemisphere according to a square grid transformed by shirley-chiu mapping using rcontrib.

Parameters

• scene (raytraverse.scene.Scene) – scene class containing geometry, location and analysis plane scene: str, optional (required if not reload) space separated list of radiance scene files (no sky) or octree

• skyres (float, optional) – approximate square patch size in degrees

• engine_args (str, optional) – rtrace arguments to pass to rcontrib

sample(vecf, vecs, outf=None)

call rendering engine to sample sky contribution

SunSampler

class raytraverse.sampler.SunSampler(scene, sun, sunbin, speclevel=9, fdres=10, engine_args='-ab 7 -ad 10 -c 100 -as 0 -lw 1.25e-5', keepamb=True, ambcache=False, slimit=0.01, maxspec=0.3, **kwargs)

Bases: raytraverse.sampler.sampler.Sampler

sample contributions from direct suns.

Parameters

• scene (raytraverse.scene.Scene) – scene class containing geometry, location and analysis plane

• sun (np.array) – shape 3, sun position

• sunbin (int) – sun bin

• ropts (str, optional) – arguments for engine

• speclevel (int, optional) – at this sampling level, pdf is made from brightness of sky sampling rather than progressive variance to look for fine scale specular highlights, this should be atleast 1 level from the end and the resolution of this level should be smaller than the size of the source

• keepamb (bool, optional) – whether to keep ambient files after run, if kept, a successive call will load these ambient files, so care must be taken to not change any parameters

• ambcache (bool, optional) – whether the rcopts indicate that the calculation will use ambient caching (and thus should write an -af file argument to the engine)

specidx = None

index of level at which brightness sampling occurs

Type

int

sunpos = None

sun position x,y,z

Type

np.array

sample(vecf, vecs, outf=None)

call rendering engine to sample sky contribution

draw(level)

draw samples based on detail calculated from weights detail is calculated across direction only as it is the most precise dimension

Returns

pdraws – index array of flattened samples chosen to sample at next level

Return type

np.array

run_callback(vecfs, name, point, posidx, vm)

handle class specific cleanup and lightpointKD construction

_load_specguide(point, posidx, vm)

run(point, posidx, vm=None, plotp=False, **kwargs)

Parameters

• point (np.array) – point to sample

• posidx (int) – position index

• vm (raytraverse.mapper.ViewMapper) – view direction to sample

• plotp – plot weights, detail and vectors for each level

• log – whether to log level sampling rates can be ‘scene’, ‘err’ or None ‘scene’ - logs to Scene log file ‘err’ - logs to stderr anything else - does not log incremental progress

• outf (bool, optional) – some inheriting classes do not need an outfile, but this should not be changed unless the class stores the lum results directly and the run_callback of the class does not expect the file to exist.

SunViewSampler

class raytraverse.sampler.SunViewSampler(scene, sun, sunbin, **kwargs)

Bases: raytraverse.sampler.sampler.Sampler

sample view rays to direct suns.

here idres and fdres are sampled on a per sun basis for a view centered on each sun direction with a view angle of .533 degrees (hardcoded in sunmapper class).

Parameters

• scene (raytraverse.scene.Scene) – scene class containing geometry, location and analysis plane

• suns (raytraverse.sunsetter.SunSetter) – sun class containing sun locations.

• loadsrc (bool) – include suns.rad in base scene initialization. if False, self.engine.load_source must be invoked before call.

ub = 1

deterministic sample draws

sample(vecf, vecs, outf=None)

call rendering engine to sample direct view rays

_offset(shape, dim)

no jitter on sun view because of very fine resolution and potentially large number of samples bog down random number generator

run_callback(vecfs, name, point, posidx, vm)

post sampling, write full resolution (including interpolated values) non zero rays to result file.

_dump_vecs(vecs, vecf)

run(point, posidx, vm=None, plotp=False, **kwargs)

Parameters

• point (np.array) – point to sample

• posidx (int) – position index

• vm (raytraverse.mapper.ViewMapper) – view direction to sample

• plotp – plot weights, detail and vectors for each level

• log – whether to log level sampling rates can be ‘scene’, ‘err’ or None ‘scene’ - logs to Scene log file ‘err’ - logs to stderr anything else - does not log incremental progress

• outf (bool, optional) – some inheriting classes do not need an outfile, but this should not be changed unless the class stores the lum results directly and the run_callback of the class does not expect the file to exist.

ImageSampler

class raytraverse.sampler.ImageSampler(scene, scalefac=None, **kwargs)

Bases: raytraverse.sampler.sampler.Sampler

sample image (for testing algorithms).

Parameters

• scene (raytraverse.scene.ImageScene) – scene class containing image file information

• scalefac (float, optional) – by default set to the average of non-zero pixels in the image used to establish sampling thresholds similar to contribution based samplers

sample(vecf, vecs, outf=None)

sample an ImageRenderer

_dump_vecs(vecs, vecf)

run_callback(vecfs, name, point, posidx, vm)

handle class specific cleanup and lightpointKD construction

DeterministicImageSampler

class raytraverse.sampler.DeterministicImageSampler(scene, scalefac=None, **kwargs)

Bases: raytraverse.sampler.imagesampler.ImageSampler

ub = 1

_offset(shape, dim)

for modifying jitter behavior of UV direction samples