def max_(a0, a1):
ar, sr = _check2(a0, a1)
if not a0.IsArithmetic:
raise Exception("max(): requires arithmetic operands!")
for i in range(sr):
ar[i] = _ek.max(a0[i], a1[i])
return ar
def __init__(self,
domain,
sample_func,
pdf_func,
sample_dim=2,
sample_count=1000000,
res=101,
ires=4):
from mitsuba.core import ScalarVector2u
if ires < 2:
raise Exception("The 'ires' parameter must be >= 2!")
self.domain = domain
self.sample_func = sample_func
self.pdf_func = pdf_func
self.sample_dim = sample_dim
self.sample_count = sample_count
self.res = ek.max(ScalarVector2u(res, int(res * domain.aspect())), 1)
self.ires = ires
self.bounds = domain.bounds()
self.pdf = None
self.histogram = None
self.p_value = None
self.messages = ''
self.fail = False
def test05_scalar(t):
if not ek.is_array_v(t) or ek.array_size_v(t) == 0:
return
get_class(t.__module__)
if ek.is_mask_v(t):
assert ek.all_nested(t(True))
assert ek.any_nested(t(True))
assert ek.none_nested(t(False))
assert ek.all_nested(t(False) ^ t(True))
assert ek.all_nested(ek.eq(t(False), t(False)))
assert ek.none_nested(ek.eq(t(True), t(False)))
if ek.is_arithmetic_v(t):
assert t(1) + t(1) == t(2)
assert t(3) - t(1) == t(2)
assert t(2) * t(2) == t(4)
assert ek.min(t(2), t(3)) == t(2)
assert ek.max(t(2), t(3)) == t(3)
if ek.is_signed_v(t):
assert t(2) * t(-2) == t(-4)
assert ek.abs(t(-2)) == t(2)
if ek.is_integral_v(t):
assert t(6) // t(2) == t(3)
assert t(7) % t(2) == t(1)
assert t(7) >> 1 == t(3)
assert t(7) << 1 == t(14)
assert t(1) | t(2) == t(3)
assert t(1) ^ t(3) == t(2)
assert t(1) & t(3) == t(1)
else:
assert t(6) / t(2) == t(3)
assert ek.sqrt(t(4)) == t(2)
assert ek.fmadd(t(1), t(2), t(3)) == t(5)
assert ek.fmsub(t(1), t(2), t(3)) == t(-1)
assert ek.fnmadd(t(1), t(2), t(3)) == t(1)
assert ek.fnmsub(t(1), t(2), t(3)) == t(-5)
assert (t(1) & True) == t(1)
assert (t(1) & False) == t(0)
assert (t(1) | False) == t(1)
assert ek.all_nested(t(3) > t(2))
assert ek.all_nested(ek.eq(t(2), t(2)))
assert ek.all_nested(ek.neq(t(3), t(2)))
assert ek.all_nested(t(1) >= t(1))
assert ek.all_nested(t(2) < t(3))
assert ek.all_nested(t(1) <= t(1))
assert ek.select(ek.eq(t(2), t(2)), t(4), t(5)) == t(4)
assert ek.select(ek.eq(t(3), t(2)), t(4), t(5)) == t(5)
t2 = t(2)
assert ek.hsum(t2) == t.Value(2 * len(t2))
assert ek.dot(t2, t2) == t.Value(4 * len(t2))
assert ek.dot_async(t2, t2) == t(4 * len(t2))
value = t(1)
value[ek.eq(value, t(1))] = t(2)
value[ek.eq(value, t(3))] = t(5)
assert value == t(2)
def __init__(self,
domain,
sample_func,
pdf_func,
sample_dim=2,
sample_count=1000000,
res=101,
ires=4):
from mitsuba.core import ScalarVector2u
assert res > 0
assert ires >= 2, "The 'ires' parameter must be >= 2!"
self.domain = domain
self.sample_func = sample_func
self.pdf_func = pdf_func
self.sample_dim = sample_dim
self.sample_count = sample_count
if domain.aspect() is None:
self.res = ScalarVector2u(res, 1)
else:
self.res = ek.max(ScalarVector2u(int(res / domain.aspect()), res),
1)
self.ires = ires
self.bounds = domain.bounds()
self.pdf = None
self.histogram = None
self.p_value = None
self.messages = ''
self.fail = False
def hmax_(a0):
size = len(a0)
if size == 0:
raise Exception("hmax(): zero-sized array!")
value = a0[0]
for i in range(1, size):
value = _ek.max(value, a0[i])
return value
def visible_ndf(D, sigma, theta_i, phi_i, isotropic):
from mitsuba.core import MarginalContinuous2D0, Vector2f
# Construct projected surface area interpolant data structure
m_sigma = MarginalContinuous2D0(sigma, normalize=False)
# Create uniform samples and warp by G2 mapping
if isotropic:
n_theta = n_phi = D.shape[1]
else:
n_phi = D.shape[0]
n_theta = D.shape[1]
# Check dimensions of micro-facet model
Dvis = np.zeros((phi_i.size, theta_i.size, n_phi, n_theta))
theta = u2theta(np.linspace(0, 1, n_theta))
phi = u2phi(np.linspace(0, 1, n_phi))
# Calculate projected area of micro-facets
for i in range(Dvis.shape[0]): # incident elevation
for j in range(Dvis.shape[1]): # incident azimuth
# Postion for sigma samples
sample = Vector2f(theta2u(theta_i[j]), phi2u(phi_i[i]))
sigma_i = m_sigma.eval(sample)
# Incident direction
omega_i = spherical2cartesian(theta_i[j], phi_i[i])
#print(np.degrees(theta_i[j]), np.degrees(phi_i[i]))
for k in range(Dvis.shape[2]): # observation azimuth
# Observation direction
omega = spherical2cartesian(theta, phi[k])
sample = Vector2f(theta2u(theta), phi2u(phi[k]))
# NDF at observation directions
if isotropic:
D_m = D[0]
else:
D_m = D[k]
# Bidirectional NDF
Dvis[i, j,
k] = ek.max(0, ek.dot(omega, omega_i)) * D_m / sigma_i
return Dvis
def test05_path_tracer_malus_law(variant_scalar_mono_polarized):
from mitsuba.core import Spectrum
from mitsuba.core.xml import load_string
from mitsuba.render import BSDFContext, TransportMode
from mitsuba.render.mueller import stokes_basis, rotate_stokes_basis_m
def spectrum_from_stokes(v):
res = Spectrum(0.0)
for i in range(4):
res[i,0] = v[i]
return res
# Test polarizer implementation inside of an actual polarized path tracer.
# (Serves also as test case for the polarized path tracer itself.)
#
# This test involves a setup using two polarizers placed along an optical
# axis between light source and camera.
# - The first polarizer is fixed, and transforms the emitted radiance into
# linearly polarized light.
# - The second polarizer rotates to different angles, thus attenuating the
# final observed intensity at the camera. We verify that this intensity
# follows Malus' law as expected.
angles = [0, 15, 30, 45, 60, 75, 90]
radiance = []
for angle in angles:
# Build scene with given polarizer rotation angle
scene_str = """<scene version='2.0.0'>
<integrator type="path"/>
<sensor type="perspective">
<float name="fov" value="0.00001"/>
<transform name="to_world">
<lookat origin="0, 10, 0"
target="0, 0, 0"
up ="0, 0, 1"/>
</transform>
<film type="hdrfilm">
<integer name="width" value="1"/>
<integer name="height" value="1"/>
<rfilter type="gaussian"/>
<string name="pixel_format" value="rgb"/>
</film>
</sensor>
<!-- Light source -->
<shape type="rectangle">
<transform name="to_world">
<rotate x="1" y="0" z="0" angle="-90"/>
<translate y="-10"/>
</transform>
<emitter type="area">
<spectrum name="radiance" value="1"/>
</emitter>
</shape>
<!-- First polarizer. Stays fixed. -->
<shape type="rectangle">
<bsdf type="polarizer"/>
<transform name="to_world">
<rotate x="1" y="0" z="0" angle="-90"/>
<translate y="-5"/>
</transform>
</shape>
<!-- Second polarizer. Rotates. -->
<shape type="rectangle">
<bsdf type="polarizer"/>
<transform name="to_world">
<rotate x="1" y="0" z="0" angle="-90"/>
<rotate x="0" y="1" z="0" angle="{}"/> <!-- Rotate around optical axis -->
<translate y="0"/>
</transform>
</shape>
</scene>""".format(angle)
scene = load_string(scene_str)
integrator = scene.integrator()
sensor = scene.sensors()[0]
sampler = sensor.sampler()
# Sample ray from sensor
ray, _ = sensor.sample_ray_differential(0.0, 0.5, [0.5, 0.5], [0.5, 0.5])
# Call integrator
value, _, _ = integrator.sample(scene, sampler, ray)
# Extract intensity from returned Stokes vector
v = value[0,0]
# Avoid occasional rounding problems
v = ek.max(0.0, v)
# Keep track of observed radiance
radiance.append(v)
# Check that Malus' law holds
for i in range(len(angles)):
theta = angles[i] * ek.pi/180
malus = ek.cos(theta)**2
malus *= radiance[0]
assert ek.allclose(malus, radiance[i], atol=1e-2)
def projected_area(D, isotropic, projected=True):
from mitsuba.core import MarginalContinuous2D0, Vector2f, Vector3f
# Check dimensions of micro-facet model
sigma = np.zeros(D.shape)
# Construct projected surface area interpolant data structure
m_D = MarginalContinuous2D0(D, normalize=False)
# Create uniform samples and warp by G2 mapping
if isotropic:
n_theta = n_phi = D.shape[1]
else:
n_phi = D.shape[0]
n_theta = D.shape[1]
theta = u2theta(np.linspace(0, 1, n_theta))
phi = u2phi(np.linspace(0, 1, n_phi))
# Temporary values for surface area calculation
theta_mean = np.zeros(n_theta + 1)
for i in range(n_theta - 1):
theta_mean[i + 1] = (theta[i + 1] - theta[i]) / 2. + theta[i]
theta_mean[-1] = theta[-1]
theta_mean[0] = theta[0]
"""
Surface area portion of unit sphere.
Conditioning better for non vectorized approach.
a = sphere_surface_patch(1, theta_next, Vector2f(phi[0], phi[1]))
"""
a = np.zeros(n_theta)
for i in range(n_theta):
a[i] = sphere_surface_patch(1, theta_mean[i:i + 2], phi[-3:-1])
# Calculate constants for integration
for j in range(n_phi):
# Interpolation points
o = spherical2cartesian(theta, phi[j])
# Postion for NDF samples
u0 = theta2u(theta)
u1 = np.ones(n_theta) * phi2u(phi[j])
if j == 0:
omega = o
u_0 = u0
u_1 = u1
area = a / 2
else:
omega = np.concatenate((omega, o))
u_0 = np.concatenate((u_0, u0))
u_1 = np.concatenate((u_1, u1))
if j == n_phi - 1:
area = np.concatenate((area, a / 2))
else:
area = np.concatenate((area, a))
sample = Vector2f(u_0, u_1)
D_s = m_D.eval(sample)
omega = Vector3f(omega)
P = 1.
# Calculate projected area of micro-facets
for i in range(sigma.shape[0] - 1):
for j in range(sigma.shape[1]):
# Get projection factor from incident and outgoind direction
if projected:
# Incident direction
omega_i = spherical2cartesian(theta[j], phi[i])
P = ek.max(0, ek.dot(omega, omega_i))
# Integrate over sphere
F = P * D_s
sigma[i, j] = np.dot(F, area)
if projected:
# Normalise
sigma[i] = sigma[i] / sigma[i, 0]
# TODO: Check for anisotropic case
if isotropic:
sigma[1] = sigma[0]
return sigma
