def test01_depth_scalar_stairs(variant_scalar_rgb):
from mitsuba.core import Ray3f
from mitsuba.render import SurfaceInteraction3f
if mitsuba.core.MTS_ENABLE_EMBREE:
pytest.skip("EMBREE enabled")
n_steps = 20
scene = make_synthetic_scene(n_steps)
n = 128
inv_n = 1.0 / (n - 1)
wavelengths = []
for x in range(n - 1):
for y in range(n - 1):
o = [x * inv_n, y * inv_n, 2]
d = [0, 0, -1]
r = Ray3f(o, d, 0.5, wavelengths)
r.mint = 0
r.maxt = 100
res_naive = scene.ray_intersect_naive(r)
res = scene.ray_intersect(r)
res_shadow = scene.ray_test(r)
step_idx = ek.floor((y * inv_n) * n_steps)
assert ek.all(res_shadow)
assert ek.all(res_shadow == res_naive.is_valid())
expected = SurfaceInteraction3f()
expected.t = 2.0 - (step_idx / n_steps)
compare_results(res_naive, expected, atol=1e-9)
compare_results(res_naive, res)
def test03_point_sample_direction_vec(variant_packet_spectral, spectrum_key):
from mitsuba.render import SurfaceInteraction3f
emitter_pos = [10, -1, 2]
emitter, spectrum = create_emitter_and_spectrum(emitter_pos, spectrum_key)
# Direction sampling
it = SurfaceInteraction3f.zero(3)
it.p = [[0.0, 0.0, 0.0], [-2.0, 0.0, -2.0], [4.5, 4.5,
0.0]] # Some positions
it.time = [0.3, 0.3, 0.3]
# Direction from the position to the point emitter
d = -it.p + emitter_pos
dist = ek.norm(d)
d /= dist
# Sample direction on the emitter
sample = [0.1, 0.5]
ds, res = emitter.sample_direction(it, sample)
assert ek.all(ds.time == it.time)
assert ek.all(ds.pdf == 1.0)
assert ek.all(ds.delta)
assert ek.allclose(ds.d, d / ek.norm(d))
# Evalutate the spectrum
spec = spectrum.eval(it) / (dist**2)
assert ek.allclose(res, spec)
def test01_construct(variant_scalar_rgb):
from mitsuba.core.xml import load_string
from mitsuba.render import ImageBlock
im = ImageBlock([33, 12], 4)
assert im is not None
assert ek.all(im.offset() == 0)
im.set_offset([10, 20])
assert ek.all(im.offset() == [10, 20])
assert ek.all(im.size() == [33, 12])
assert im.warn_invalid()
assert im.border_size() == 0 # Since there's no reconstruction filter
assert im.channel_count() == 4
assert im.data() is not None
rfilter = load_string("""<rfilter version="2.0.0" type="gaussian">
<float name="stddev" value="15"/>
</rfilter>""")
im = ImageBlock([10, 11], 2, filter=rfilter, warn_invalid=False)
assert im.border_size() == rfilter.border_size()
assert im.channel_count() == 2
assert not im.warn_invalid()
im = ImageBlock([10, 11], 6)
assert im is not None
im.channel_count() == 6
def test03_clone(variant_scalar_rgb, sampler):
"""After cloning, the new sampler should *not* yield the same values: it
should automatically be seeded differently rather than copying the exact
state of the original sampler."""
sampler2 = sampler.clone()
for i in range(5):
assert ek.all(sampler.next_1d() != sampler2.next_1d())
assert ek.all(sampler.next_2d() != sampler2.next_2d())
def test02_inverse(variant_scalar_rgb):
from mitsuba.core import Transform4f, Matrix4f
p = [1, 2, 3]
def check_inverse(tr, expected):
inv_trafo = tr.inverse()
assert ek.allclose(inv_trafo.matrix, np.array(expected)), \
'\n' + str(inv_trafo.matrix) + '\n' + str(expected)
assert ek.allclose(inv_trafo.transform_point(tr.transform_point(p)),
p,
rtol=1e-4)
# --- Scale
trafo = Transform4f.scale([1.0, 10.0, 500.0])
assert ek.all(trafo.matrix == np.array([[1, 0, 0, 0], [0, 10, 0, 0],
[0, 0, 500, 0], [0, 0, 0, 1]]))
assert ek.all(trafo.transform_point(p) == np.array([1, 20, 1500]))
check_inverse(trafo, [[1, 0, 0, 0], [0, 1 / 10.0, 0, 0],
[0, 0, 1 / 500.0, 0], [0, 0, 0, 1]])
# --- Translation
trafo = Transform4f.translate([1, 0, 1.5])
assert ek.all(trafo.matrix == np.array([
[1, 0, 0, 1],
[0, 1, 0, 0],
[0, 0, 1, 1.5],
[0, 0, 0, 1],
]))
assert ek.all(trafo.transform_point(p) == np.array([2, 2, 4.5]))
check_inverse(trafo,
[[1, 0, 0, -1], [0, 1, 0, 0], [0, 0, 1, -1.5], [0, 0, 0, 1]])
# --- Perspective x_fov, near clip, far clip
trafo = Transform4f.perspective(34.022, 1, 1000)
# Spot-checked against a known transform from Mitsuba1.
expected = np.array([[3.26860189, 0, 0, 0], [0, 3.26860189, 0, 0],
[0, 0, 1.001001, -1.001001], [0, 0, 1, 0]])
assert ek.allclose(trafo.matrix, expected)
check_inverse(trafo, la.inv(expected))
for i in range(10):
mtx = np.random.random((4, 4))
inv_ref = la.inv(mtx)
trafo = Transform4f(mtx)
inv_val = trafo.inverse_transpose.T
assert ek.all(trafo.matrix == mtx)
assert la.norm(inv_ref - inv_val, 'fro') / la.norm(inv_val,
'fro') < 5e-4
p = np.random.random((3, ))
res = trafo.inverse().transform_point(trafo.transform_point(p))
assert la.norm(res - p, 2) < 5e-3
def test02_bbox(variant_scalar_rgb):
from mitsuba.core import xml
for r in [1, 2, 4]:
s = xml.load_dict({"type": "sphere", "radius": r})
b = s.bbox()
assert b.valid()
assert ek.allclose(b.center(), [0, 0, 0])
assert ek.all(b.min == -r)
assert ek.all(b.max == r)
assert ek.allclose(b.extents(), [2 * r] * 3)
def test02_small_film(variant_scalar_rgb):
from mitsuba.render import Spiral
f = make_film(15, 12)
s = Spiral(f.size(), f.crop_offset())
(bo, bs, bi) = s.next_block()
assert ek.all(bo == [0, 0])
assert ek.all(bs == [15, 12])
assert ek.all(bi == 0)
# The whole image is covered by a single block
assert ek.all(s.next_block()[1] == 0)
def test02_bbox(variant_scalar_rgb):
if mitsuba.core.MTS_ENABLE_EMBREE:
pytest.skip("EMBREE enabled")
for r in [1, 2, 4]:
s = example_sphere(r)
b = s.bbox()
assert b.valid()
assert ek.allclose(b.center(), [0, 0, 0])
assert ek.all(b.min == -r)
assert ek.all(b.max == r)
assert ek.allclose(b.extents(), [2 * r] * 3)
def test02_fresnel_polarized_packet(variant_packet_rgb):
from mitsuba.render import fresnel
cos_theta_i = ek.linspace(Float, -1, 1, 20)
F, cos_theta_t, _, scale = fresnel(cos_theta_i, 1)
assert ek.all(F == Float.zero(20))
assert ek.allclose(cos_theta_t, -cos_theta_i, atol=5e-7)
def test03_depth_packet_stairs(variant_packet_rgb):
from mitsuba.core import Ray3f as Ray3fX, Properties
from mitsuba.render import Scene
if mitsuba.core.MTS_ENABLE_EMBREE:
pytest.skip("EMBREE enabled")
props = Properties("scene")
props["_unnamed_0"] = create_stairs_packet(11)
scene = Scene(props)
mitsuba.set_variant("scalar_rgb")
from mitsuba.core import Ray3f, Vector3f
n = 4
inv_n = 1.0 / (n - 1)
rays = Ray3fX.zero(n * n)
d = [0, 0, -1]
wavelengths = []
for x in range(n):
for y in range(n):
o = Vector3f(x * inv_n, y * inv_n, 2)
o = o * 0.999 + 0.0005
rays[x * n + y] = Ray3f(o, d, 0, 100, 0.5, wavelengths)
res_naive = scene.ray_intersect_naive(rays)
res = scene.ray_intersect(rays)
res_shadow = scene.ray_test(rays)
# TODO: spot-check (here, we only check consistency)
assert ek.all(res_shadow == res.is_valid())
compare_results(res_naive, res, atol=1e-6)
def test01_position_sample_construction_single(variant_scalar_rgb):
from mitsuba.render import PositionSample3f, SurfaceInteraction3f
record = PositionSample3f()
record.p = [0, 42, 0]
record.n = [0, 0, 0.4]
record.uv = [1, 2]
record.pdf = 0.002
record.delta = False
record.time = 0
record.object = None
assert str(record) == """PositionSample3f[
p = [0, 42, 0],
n = [0, 0, 0.4],
uv = [1, 2],
time = 0,
pdf = 0.002,
delta = 0,
object = nullptr
]"""
# SurfaceInteraction constructor
si = SurfaceInteraction3f()
si.time = 50.5
si.uv = [0.1, 0.8]
record = PositionSample3f(si)
assert record.time == si.time \
and ek.all(record.uv == si.uv) \
and record.pdf == 0.0
def test40_safe_functions(m):
x = ek.linspace(m.Float, 0, 1, 10)
y = ek.linspace(m.Float, -1, 1, 10)
z = ek.linspace(m.Float, -1, 1, 10)
ek.enable_grad(x, y, z)
x2 = ek.safe_sqrt(x)
y2 = ek.safe_acos(y)
z2 = ek.safe_asin(z)
ek.backward(x2)
ek.backward(y2)
ek.backward(z2)
assert ek.grad(x)[0] == 0
assert ek.allclose(ek.grad(x)[1], .5 / ek.sqrt(1 / 9))
assert x[0] == 0
assert ek.all(ek.isfinite(ek.grad(x)))
assert ek.all(ek.isfinite(ek.grad(y)))
assert ek.all(ek.isfinite(ek.grad(z)))
def sample_functor(sample, *args):
n = ek.slices(sample)
plugin = instantiate(args)
(si, ctx) = make_context(n)
bs, weight = plugin.sample(ctx, si, sample[0], [sample[1], sample[2]])
w = Float.full(1.0, ek.slices(weight))
w[ek.all(ek.eq(weight, 0))] = 0
return bs.wo, w
def test03_ray_intersect(variant_scalar_rgb):
from mitsuba.core import xml, Ray3f, Transform4f
# Scalar
scene = xml.load_dict({
"type": "scene",
"foo": {
"type": "rectangle",
"to_world": Transform4f.scale((2.0, 0.5, 1.0))
}
})
n = 15
coords = ek.linspace(Float, -1, 1, n)
rays = [
Ray3f(o=[a, a, 5], d=[0, 0, -1], time=0.0, wavelengths=[])
for a in coords
]
si_scalar = []
valid_count = 0
for i in range(n):
its_found = scene.ray_test(rays[i])
si = scene.ray_intersect(rays[i])
assert its_found == (abs(coords[i]) <= 0.5)
assert si.is_valid() == its_found
si_scalar.append(si)
valid_count += its_found
assert valid_count == 7
try:
mitsuba.set_variant('packet_rgb')
from mitsuba.core import xml, Ray3f as Ray3fX
except ImportError:
pytest.skip("packet_rgb mode not enabled")
# Packet
scene_p = xml.load_dict({
"type": "scene",
"foo": {
"type": "rectangle",
"to_world": Transform4f.scale((2.0, 0.5, 1.0))
}
})
packet = Ray3fX.zero(n)
for i in range(n):
packet[i] = rays[i]
si_p = scene_p.ray_intersect(packet)
its_found_p = scene_p.ray_test(packet)
assert ek.all(si_p.is_valid() == its_found_p)
for i in range(n):
assert ek.allclose(si_p.t[i], si_scalar[i].t)
def make_film(width=156, height=232):
from mitsuba.core.xml import load_string
f = load_string("""<film type="hdrfilm" version="2.0.0">
<integer name="width" value="{}"/>
<integer name="height" value="{}"/>
</film>""".format(width, height))
assert f is not None
assert ek.all(f.size() == [width, height])
return f
def test09_eval_parameterization(variant_scalar_rgb, variant_packet_rgb):
from mitsuba.core.xml import load_string
shape = load_string('''
<shape type="obj" version="2.0.0">
<string name="filename" value="resources/data/common/meshes/rectangle.obj"/>
</shape>
''')
print(shape)
si = shape.eval_parameterization([-0.01, 0.5])
assert not ek.any(si.is_valid())
si = shape.eval_parameterization([1.0 - 1e-7, 1.0 - 1e-7])
assert ek.all(si.is_valid())
assert ek.allclose(si.p, [1, 1, 0])
si = shape.eval_parameterization([1e-7, 1e-7])
assert ek.all(si.is_valid())
assert ek.allclose(si.p, [-1, -1, 0])
si = shape.eval_parameterization([.2, .3])
assert ek.all(si.is_valid())
assert ek.allclose(si.p, [-.6, -.4, 0])
def test47_nan_propagation(m):
for i in range(2):
x = ek.arange(m.Float, 10)
ek.enable_grad(x)
f0 = m.Float(0)
y = ek.select(x < (20 if i == 0 else 0), x, x * (f0 / f0))
ek.backward(y)
g = ek.grad(x)
if i == 0:
assert g == 1
else:
assert ek.all(ek.isnan(g))
for i in range(2):
x = ek.arange(m.Float, 10)
ek.enable_grad(x)
f0 = m.Float(0)
y = ek.select(x < (20 if i == 0 else 0), x, x * (f0 / f0))
ek.forward(x)
g = ek.grad(y)
if i == 0:
assert g == 1
else:
assert ek.all(ek.isnan(g))
def test_sample_ray(variant_packet_spectral, spectrum_key, wavelength_sample,
pos_sample, cutoff_angle, lookat):
# Check the correctness of the sample_ray() method
import math
from mitsuba.core import warp, sample_shifted, Transform4f
from mitsuba.render import SurfaceInteraction3f
cutoff_angle_rad = math.radians(cutoff_angle)
cos_cutoff_angle_rad = math.cos(cutoff_angle_rad)
beam_width_rad = cutoff_angle_rad * 0.75
inv_transition_width = 1 / (cutoff_angle_rad - beam_width_rad)
emitter, spectrum = create_emitter_and_spectrum(lookat, cutoff_angle,
spectrum_key)
eval_t = 0.3
trafo = Transform4f(emitter.world_transform().eval(eval_t))
# Sample a local direction and calculate local angle
dir_sample = pos_sample # not being used anyway
local_dir = warp.square_to_uniform_cone(pos_sample, cos_cutoff_angle_rad)
angle = ek.acos(local_dir[2])
angle = ek.select(
ek.abs(angle - beam_width_rad) < 1e-3, beam_width_rad, angle)
angle = ek.select(
ek.abs(angle - cutoff_angle_rad) < 1e-3, cutoff_angle_rad, angle)
# Sample a ray (position, direction, wavelengths) from the emitter
ray, res = emitter.sample_ray(eval_t, wavelength_sample, pos_sample,
dir_sample)
# Sample wavelengths on the spectrum
it = SurfaceInteraction3f.zero()
wav, spec = spectrum.sample(it, sample_shifted(wavelength_sample))
it.wavelengths = wav
spec = spectrum.eval(it)
spec = ek.select(
angle <= beam_width_rad, spec,
spec * ((cutoff_angle_rad - angle) * inv_transition_width))
spec = ek.select(angle <= cutoff_angle_rad, spec, 0)
assert ek.allclose(
res, spec / warp.square_to_uniform_cone_pdf(
trafo.inverse().transform_vector(ray.d), cos_cutoff_angle_rad))
assert ek.allclose(ray.time, eval_t)
assert ek.all(local_dir.z >= cos_cutoff_angle_rad)
assert ek.allclose(ray.wavelengths, wav)
assert ek.allclose(ray.d, trafo.transform_vector(local_dir))
assert ek.allclose(ray.o, lookat["pos"])
def test12_binary_search(cname):
t = get_class(cname)
import numpy as np
data_np = np.float32(np.sort(np.random.normal(size=10000)))
search_np = np.float32(np.random.normal(size=10000))
data = t(data_np)
search = t(search_np)
index = ek.binary_search(0,
len(data) - 1,
lambda index: ek.gather(t, data, index) < search)
value = ek.gather(t, data, index)
cond = ek.eq(index, len(data) - 1) | (value >= search)
assert ek.all(cond)
def test06_discr_bruteforce(variant_packet_rgb):
# Brute force validation of discrete distribution sampling
from mitsuba.core import DiscreteDistribution, Float, PCG32, UInt64
rng = PCG32(initseq=UInt64.arange(50))
for size in range(2, 20):
for i in range(2, 50):
density = Float(rng.next_uint32_bounded(i)[0:size])
if ek.hsum(density) == 0:
continue
ddistr = DiscreteDistribution(density)
x = ek.linspace(Float, 0, 1, 20)
y = ddistr.sample(x)
z = ek.gather(ddistr.cdf(), y - 1, y > 0)
x *= ddistr.sum()
# Did we sample the right interval?
assert ek.all((x > z) | (ek.eq(x, 0) & (x >= z)))
def test02_position_sample_construction_dynamic(variant_packet_rgb):
from mitsuba.render import PositionSample3f, SurfaceInteraction3f
n_records = 5
records = PositionSample3f.zero(n_records)
# Set properties for all records at once (SoA style)
# records.n = np.zeros(shape=(n_records, 3))
# records.pdf = np.zeros(shape=(n_records,))
# records.uv = np.zeros(shape=(n_records, 2))
# records.delta = np.zeros(shape=(n_records,), dtype=np.bool)
records.p = np.array([[1.0, 1.0, 1.0], [0.9, 0.9, 0.9], [0.7, 0.7, 0.7],
[1.2, 1.5, 1.1], [1.5, 1.5, 1.5]])
records.time = [0.0, 0.5, 0.7, 1.0, 1.5]
assert str(records) == """PositionSample3fX[
p = [[1, 1, 1],
[0.9, 0.9, 0.9],
[0.7, 0.7, 0.7],
[1.2, 1.5, 1.1],
[1.5, 1.5, 1.5]],
n = [[0, 0, 0],
[0, 0, 0],
[0, 0, 0],
[0, 0, 0],
[0, 0, 0]],
uv = [[0, 0],
[0, 0],
[0, 0],
[0, 0],
[0, 0]],
time = [0, 0.5, 0.7, 1, 1.5],
pdf = [0, 0, 0, 0, 0],
delta = [0, 0, 0, 0, 0],
object = [nullptr, nullptr, nullptr, nullptr, nullptr]
]"""
# SurfaceInteraction constructor
si = SurfaceInteraction3f.zero(n_records)
si.time = [0.0, 0.5, 0.7, 1.0, 1.5]
records = PositionSample3f(si)
assert ek.all(records.time == si.time)
def test02_depth_scalar_bunny(variant_scalar_rgb):
from mitsuba.core import Ray3f, BoundingBox3f
from mitsuba.core.xml import load_string
from mitsuba.render import SurfaceInteraction3f
if mitsuba.core.MTS_ENABLE_EMBREE:
pytest.skip("EMBREE enabled")
scene = load_string("""
<scene version="0.5.0">
<shape type="ply">
<string name="filename" value="resources/data/ply/bunny_lowres.ply"/>
</shape>
</scene>
""")
b = scene.bbox()
n = 100
inv_n = 1.0 / (n - 1)
wavelengths = []
for x in range(n):
for y in range(n):
o = [
b.min[0] * (1 - x * inv_n) + b.max[0] * x * inv_n,
b.min[1] * (1 - y * inv_n) + b.max[1] * y * inv_n, b.min[2]
]
d = [0, 0, 1]
r = Ray3f(o, d, 0.5, wavelengths)
r.mint = 0
r.maxt = 100
res_naive = scene.ray_intersect_naive(r)
res = scene.ray_intersect(r)
res_shadow = scene.ray_test(r)
assert ek.all(res_shadow == res_naive.is_valid())
compare_results(res_naive, res)
def test02_crops(variant_scalar_rgb):
from mitsuba.core.xml import load_string
film = load_string("""<film version="2.0.0" type="hdrfilm">
<integer name="width" value="32"/>
<integer name="height" value="21"/>
<integer name="crop_width" value="11"/>
<integer name="crop_height" value="5"/>
<integer name="crop_offset_x" value="2"/>
<integer name="crop_offset_y" value="3"/>
<boolean name="high_quality_edges" value="true"/>
<string name="pixel_format" value="rgba"/>
</film>""")
assert film is not None
assert ek.all(film.size() == [32, 21])
assert ek.all(film.crop_size() == [11, 5])
assert ek.all(film.crop_offset() == [2, 3])
assert film.has_high_quality_edges()
# Crop size doesn't adjust its size, so an error should be raised if the
# resulting crop window goes out of bounds.
incomplete = """<film version="2.0.0" type="hdrfilm">
<integer name="width" value="32"/>
<integer name="height" value="21"/>
<integer name="crop_offset_x" value="30"/>
<integer name="crop_offset_y" value="20"/>"""
with pytest.raises(RuntimeError):
film = load_string(incomplete + "</film>")
film = load_string(incomplete + """
<integer name="crop_width" value="2"/>
<integer name="crop_height" value="1"/>
</film>""")
assert film is not None
assert ek.all(film.size() == [32, 21])
assert ek.all(film.crop_size() == [2, 1])
assert ek.all(film.crop_offset() == [30, 20])
def test08_morton3(variant_scalar_rgb):
from mitsuba.core import math
v0 = [123, 456, 789]
v1 = math.morton_encode3(v0)
v2 = math.morton_decode3(v1)
assert ek.all(v0 == v2)
def compare_results(res_a, res_b, atol=0.0):
assert ek.all(res_a.is_valid() == res_b.is_valid())
if ek.any(res_a.is_valid()):
assert ek.allclose(res_a.t, res_b.t,
atol=atol), "\n%s\n\n%s" % (res_a.t, res_b.t)
def test02_sample_pol_local(variant_scalar_mono_polarized):
from mitsuba.core import Frame3f, Transform4f, Spectrum, UnpolarizedSpectrum, Vector3f
from mitsuba.core.xml import load_string
from mitsuba.render import BSDFContext, TransportMode, SurfaceInteraction3f, fresnel_conductor
from mitsuba.render.mueller import stokes_basis, rotate_mueller_basis
def spectrum_from_stokes(v):
res = Spectrum(0.0)
for i in range(4):
res[i, 0] = v[i]
return res
# Create a Silver conductor BSDF and reflect different polarization states
# at a 45˚ angle.
# All tests take place directly in local BSDF coordinates. Here we only
# want to make sure that the output of this looks like what you would
# expect from a Mueller matrix describing specular reflection on a mirror.
eta = 0.136125 + 4.010625j # IoR values of Ag at 635.816284nm
bsdf = load_string("""<bsdf version='2.0.0' type='conductor'>
<spectrum name="eta" value="{}"/>
<spectrum name="k" value="{}"/>
</bsdf>""".format(eta.real, eta.imag))
theta_i = 45 * ek.pi / 180
wi = Vector3f([-ek.sin(theta_i), 0, ek.cos(theta_i)])
ctx = BSDFContext()
ctx.mode = TransportMode.Importance
si = SurfaceInteraction3f()
si.p = [0, 0, 0]
si.wi = wi
n = [0, 0, 1]
si.sh_frame = Frame3f(n)
bs, M_local = bsdf.sample(ctx, si, 0.0, [0.0, 0.0])
wo = bs.wo
# Rotate into standard coordinates for specular reflection
bi_s = ek.normalize(ek.cross(n, -wi))
bi_p = ek.normalize(ek.cross(-wi, bi_s))
bo_s = ek.normalize(ek.cross(n, wo))
bo_p = ek.normalize(ek.cross(wo, bi_s))
M_local = rotate_mueller_basis(M_local, -wi, stokes_basis(-wi), bi_p, wo,
stokes_basis(wo), bo_p)
# Apply to unpolarized light and verify that it is equivalent to normal Fresnel
a0 = M_local @ spectrum_from_stokes([1, 0, 0, 0])
F = fresnel_conductor(ek.cos(theta_i),
ek.scalar.Complex2f(eta.real, eta.imag))
a0 = a0[0, 0]
assert ek.allclose(a0[0], F, atol=1e-3)
# Apply to horizontally polarized light (linear at 0˚)
# Test that it is..
# 1) still fully polarized (though with reduced intensity)
# 2) still horizontally polarized
a1 = M_local @ spectrum_from_stokes([1, +1, 0, 0])
assert ek.allclose(a1[0, 0], ek.abs(a1[1, 0]), atol=1e-3) # 1)
a1 /= a1[0, 0]
assert ek.allclose(a1, spectrum_from_stokes([1, 1, 0, 0]), atol=1e-3) # 2)
# Apply to vertically polarized light (linear at 90˚)
# Test that it is..
# 1) still fully polarized (though with reduced intensity)
# 2) still vertically polarized
a2 = M_local @ spectrum_from_stokes([1, -1, 0, 0])
assert ek.allclose(a2[0, 0], ek.abs(a2[1, 0]), atol=1e-3) # 1)
a2 /= a2[0, 0]
assert ek.allclose(a2, spectrum_from_stokes([1, -1, 0, 0]),
atol=1e-3) # 2)
# Apply to (positive) diagonally polarized light (linear at +45˚)
# Test that..
# 1) The polarization is flipped to -45˚
# 2) There is now also some (left) circular polarization
a3 = M_local @ spectrum_from_stokes([1, 0, +1, 0])
assert ek.all(a3[2, 0] < UnpolarizedSpectrum(0.0))
assert ek.all(a3[3, 0] < UnpolarizedSpectrum(0.0))
# Apply to (negative) diagonally polarized light (linear at -45˚)
# Test that..
# 1) The polarization is flipped to +45˚
# 2) There is now also some (right) circular polarization
a4 = M_local @ spectrum_from_stokes([1, 0, -1, 0])
assert ek.all(a4[2, 0] > UnpolarizedSpectrum(0.0))
assert ek.all(a4[3, 0] > UnpolarizedSpectrum(0.0))
# Apply to right circularly polarized light
# Test that the polarization is flipped to left circular
a5 = M_local @ spectrum_from_stokes([1, 0, 0, +1])
assert ek.all(a5[3, 0] < UnpolarizedSpectrum(0.0))
# Apply to left circularly polarized light
# Test that the polarization is flipped to right circular
a6 = M_local @ spectrum_from_stokes([1, 0, 0, -1])
assert ek.all(a6[3, 0] > UnpolarizedSpectrum(0.0))
def test03_ray_intersect(variant_scalar_rgb):
if mitsuba.core.MTS_ENABLE_EMBREE:
pytest.skip("EMBREE enabled")
from mitsuba.core.xml import load_string
from mitsuba.core import Ray3f
# Scalar
scene = load_string("""<scene version="2.0.0">
<shape type="rectangle">
<transform name="to_world">
<scale x="2" y="0.5" z="1"/>
</transform>
</shape>
</scene>""")
n = 15
coords = ek.linspace(Float, -1, 1, n)
rays = [
Ray3f(o=[a, a, 5], d=[0, 0, -1], time=0.0, wavelengths=[])
for a in coords
]
si_scalar = []
valid_count = 0
for i in range(n):
# print(rays[i])
its_found = scene.ray_test(rays[i])
si = scene.ray_intersect(rays[i])
assert its_found == (abs(coords[i]) <= 0.5)
assert si.is_valid() == its_found
si_scalar.append(si)
valid_count += its_found
assert valid_count == 7
try:
mitsuba.set_variant('packet_rgb')
from mitsuba.core.xml import load_string as load_string_packet
from mitsuba.core import Ray3f as Ray3fX
except ImportError:
pytest.skip("packet_rgb mode not enabled")
# Packet
scene_p = load_string_packet("""<scene version="2.0.0">
<shape type="rectangle">
<transform name="to_world">
<scale x="2" y="0.5" z="1"/>
</transform>
</shape>
</scene>""")
packet = Ray3fX.zero(n)
for i in range(n):
packet[i] = rays[i]
si_p = scene_p.ray_intersect(packet)
its_found_p = scene_p.ray_test(packet)
assert ek.all(si_p.is_valid() == its_found_p)
for i in range(n):
assert ek.allclose(si_p.t[i], si_scalar[i].t)
def test02_sample_pol_world(variant_scalar_mono_polarized):
from mitsuba.core import Frame3f, Spectrum, UnpolarizedSpectrum
from mitsuba.core.xml import load_string
from mitsuba.render import BSDFContext, TransportMode, SurfaceInteraction3f, fresnel_conductor
from mitsuba.render.mueller import stokes_basis, rotate_mueller_basis
def spectrum_from_stokes(v):
res = Spectrum(0.0)
for i in range(4):
res[i, 0] = v[i]
return res
# Create a Silver conductor BSDF and reflect different polarization states
# at a 45˚ angle.
# This test takes place in world coordinates and thus involves additional
# coordinate system rotations.
#
# The setup is as follows:
# - The mirror is positioned at [0, 0, 0], angled s.t. the surface normal
# is along [1, 1, 0].
# - Incident ray w1 = [-1, 0, 0] strikes the mirror at a 45˚ angle and
# reflects into direction w2 = [0, 1, 0]
# - The corresponding Stokes bases are b1 = [0, 1, 0] and b2 = [1, 0, 0].
# Setup
eta = 0.136125 + 4.010625j # IoR values of Ag at 635.816284nm
bsdf = load_string("""<bsdf version='2.0.0' type='conductor'>
<spectrum name="eta" value="{}"/>
<spectrum name="k" value="{}"/>
</bsdf>""".format(eta.real, eta.imag))
ctx = BSDFContext()
ctx.mode = TransportMode.Importance
si = SurfaceInteraction3f()
si.p = [0, 0, 0]
si.n = ek.normalize([1.0, 1.0, 0.0])
si.sh_frame = Frame3f(si.n)
# Incident / outgoing directions and their Stokes bases
w1 = ek.scalar.Vector3f([-1, 0, 0])
b1 = [0, 1, 0]
w2 = ek.scalar.Vector3f([0, 1, 0])
b2 = [1, 0, 0]
# Perform actual reflection
si.wi = si.to_local(-w1)
bs, M_tmp = bsdf.sample(ctx, si, 0.0, [0.0, 0.0])
M_world = si.to_world_mueller(M_tmp, -si.wi, bs.wo)
# Test that outgoing direction is as predicted
assert ek.allclose(si.to_world(bs.wo), w2, atol=1e-5)
# Align reference frames s.t. polarization is expressed w.r.t. b1 & b2
M_world = rotate_mueller_basis(M_world, w1, stokes_basis(w1), b1, w2,
stokes_basis(w2), b2)
# Apply to unpolarized light and verify that it is equivalent to normal Fresnel
a0 = M_world @ spectrum_from_stokes([1, 0, 0, 0])
F = fresnel_conductor(si.wi[2], ek.scalar.Complex2f(eta.real, eta.imag))
a0 = a0[0, 0]
assert ek.allclose(a0[0], F, atol=1e-3)
# Apply to horizontally polarized light (linear at 0˚)
# Test that it is..
# 1) still fully polarized (though with reduced intensity)
# 2) still horizontally polarized
a1 = M_world @ spectrum_from_stokes([1, +1, 0, 0])
assert ek.allclose(a1[0, 0], ek.abs(a1[1, 0]), atol=1e-3) # 1)
a1 /= a1[0, 0]
assert ek.allclose(a1, spectrum_from_stokes([1, 1, 0, 0]), atol=1e-3) # 2)
# Apply to vertically polarized light (linear at 90˚)
# Test that it is..
# 1) still fully polarized (though with reduced intensity)
# 2) still vertically polarized
a2 = M_world @ spectrum_from_stokes([1, -1, 0, 0])
assert ek.allclose(a2[0, 0], ek.abs(a2[1, 0]), atol=1e-3) # 1)
a2 /= a2[0, 0]
assert ek.allclose(a2, spectrum_from_stokes([1, -1, 0, 0]),
atol=1e-3) # 2)
# Apply to (positive) diagonally polarized light (linear at +45˚)
# Test that..
# 1) The polarization is flipped to -45˚
# 2) There is now also some (left) circular polarization
a3 = M_world @ spectrum_from_stokes([1, 0, +1, 0])
assert ek.all(a3[2, 0] < UnpolarizedSpectrum(0.0))
assert ek.all(a3[3, 0] < UnpolarizedSpectrum(0.0))
# Apply to (negative) diagonally polarized light (linear at -45˚)
# Test that..
# 1) The polarization is flipped to +45˚
# 2) There is now also some (right) circular polarization
a4 = M_world @ spectrum_from_stokes([1, 0, -1, 0])
assert ek.all(a4[2, 0] > UnpolarizedSpectrum(0.0))
assert ek.all(a4[3, 0] > UnpolarizedSpectrum(0.0))
# Apply to right circularly polarized light
# Test that the polarization is flipped to left circular
a5 = M_world @ spectrum_from_stokes([1, 0, 0, +1])
assert ek.all(a5[3, 0] < UnpolarizedSpectrum(0.0))
# Apply to left circularly polarized light
# Test that the polarization is flipped to right circular
a6 = M_world @ spectrum_from_stokes([1, 0, 0, -1])
assert ek.all(a6[3, 0] > UnpolarizedSpectrum(0.0))
def test02_sample_vs_pcg32(variant_scalar_rgb, sampler):
# IndependentSampler uses the default-constructed PCG if no seed is provided.
ref = ek.scalar.PCG32()
for i in range(10):
assert ek.all(sampler.next_1d() == next_float(ref))
assert ek.all(sampler.next_2d() == [next_float(ref), next_float(ref)])
def tabulate_histogram(self):
"""
Invoke the provided sampling strategy many times and generate a
histogram in the parameter domain. If ``sample_func`` returns a tuple
``(positions, weights)`` instead of just positions, the samples are
considered to be weighted.
"""
# Generate a table of uniform variates
from mitsuba.core import Float, Vector2f, Vector2u, Float32, \
UInt64, PCG32
rng = PCG32(initseq=ek.arange(UInt64, self.sample_count))
samples_in = getattr(mitsuba.core, 'Vector%if' % self.sample_dim)()
for i in range(self.sample_dim):
samples_in[i] = rng.next_float32() if Float is Float32 \
else rng.next_float64()
self.pdf_start = time.time()
# Invoke sampling strategy
samples_out = self.sample_func(samples_in)
if type(samples_out) is tuple:
weights_out = samples_out[1]
samples_out = samples_out[0]
else:
weights_out = Float(1.0)
# Map samples into the parameter domain
xy = self.domain.map_backward(samples_out)
# Sanity check
eps = self.bounds.extents() * 1e-4
in_domain = ek.all((xy >= self.bounds.min - eps)
& (xy <= self.bounds.max + eps))
if not ek.all(in_domain):
self._log('Encountered samples outside of the specified '
'domain: %s' % str(ek.compress(xy, ~in_domain)))
self.fail = True
# Normalize position values
xy = (xy - self.bounds.min) / self.bounds.extents()
xy = Vector2u(
ek.clamp(xy * Vector2f(self.res), 0, Vector2f(self.res - 1)))
# Compute a histogram of the positions in the parameter domain
self.histogram = ek.zero(Float, ek.hprod(self.res))
ek.scatter_add(target=self.histogram,
index=xy.x + xy.y * self.res.x,
source=weights_out)
self.pdf_end = time.time()
histogram_min = ek.hmin(self.histogram)
if not histogram_min >= 0:
self._log('Encountered a cell with negative sample '
'weights: %f' % histogram_min)
self.fail = True
self.histogram_sum = ek.hsum(self.histogram) / self.sample_count
if self.histogram_sum > 1.1:
self._log('Sample weights add up to a value greater '
'than 1.0: %f' % self.histogram_sum)
self.fail = True
