raytraverse.sampler

Sampler

class raytraverse.sampler.Sampler(scene, fdres=9, srcn=1, accuracy=1.0, idres=4, stype='generic', srcdef=None, plotp=False, bands=1, engine_args='', nproc=None, **kwargs)

Bases: object

base sampling class

To implement a proper-subclass an engine attribute must be set to a renderer instance prior to calling Sampler.__init__. Also, the method sample must be overriden to properly set up arguments for the renderer.call

Parameters

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

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

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

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

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

• 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()

engine = None

bands = None

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

Type

int

samplemap = None

mapper to use for sampling

Type

func

srcn = None

number of sources return per vector by run

Type

int

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 idx

index of next level to sample

Type

int

property levels

sampling scheme

Getter

Returns the sampling scheme

Setter

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

Type

np.array

property scene

scene information

Getter

Returns this sampler’s scene

Setter

Set this sampler’s scene and create octree with source desc

Type

raytraverse.scene.Scene

sample(vecf)

generic sample function

_uv2xyz(uv, si)

including to allow overriding mapping bevahior of daughter classes

sample_idx(pdraws)

generate samples vectors from flat draw indices

Parameters

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

Returns

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

• vecs (np.array) – sample vectors

dump_vecs(vecs, si=None)

save vectors to file

Parameters

• vecs (np.array) – ray directions to write

• si (np.array, optional) – sample indices

draw()

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

update_pdf(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()

get_scheme()

run()

execute sampler

SCBinSampler

class raytraverse.sampler.SCBinSampler(scene, accuracy=1, rcopts='-ab 7 -ad 60000 -as 30000 -lw 1e-7', **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

• srcn (int, optional) – side of square sky resolution

sample(vecf)

call rendering engine to sample sky contribution

Parameters

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

Returns

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

Return type

np.array

SunSampler

class raytraverse.sampler.SunSampler(scene, suns, plotp=False, **kwargs)

Bases: object

factory class for SingleSunSamplers.

Parameters

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

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

viewsampler = None

raytraverse.sampler.SunViewSampler

sampleargs = None

sampling arguments for SingleSunSampler

Type

dict

reflsampler = None

raytraverse.sampler.SingleSunSampler

run(view=True, reflection=True)

SingleSunSampler

class raytraverse.sampler.SingleSunSampler(scene, suns, sidx, speclevel=9, fdres=10, accuracy=1, rcopts='-ab 6 -ad 3000 -as 1500 -st 0 -ss 16 -aa .1', keepamb=False, ambcache=True, **kwargs)

Bases: raytraverse.sampler.sampler.Sampler

sample contributions from direct suns.

Parameters

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

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

• sidx (int) – sun index to sample

• 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)

slimit = None

controls sampling limit in case of limited contribution

Type

float

specidx = None

index of level at which brightness sampling occurs

Type

int

sunpos = None

sun position x,y,z

Type

np.array

pdf_from_sky(skyfield, interp=12, rebuild=False, zero=True, filterpts=True)

sample(vecf)

call rendering engine to sample sky contribution

Parameters

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

Returns

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

Return type

np.array

draw()

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

SunViewSampler

class raytraverse.sampler.SunViewSampler(scene, suns, **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.

property levels

sampling scheme

Getter

Returns the sampling scheme

Setter

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

Type

np.array

check_viz()

sample(vecf)

call rendering engine to sample direct view rays

Parameters

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

Returns

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

Return type

np.array

_uv2xyz(uv, si)

including to allow overriding mapping bevahior of daughter classes

draw()

draw first level based on sky visibility

run_callback()

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