def test02_point_sample_direction(variant_scalar_spectral, spectrum_key):
# Check the correctness of the sample_direction() method
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()
it.p = [0.0, -2.0, 4.5] # Some position
it.time = 0.3
# Direction from the position to the point emitter
d = -it.p + emitter_pos
dist = ek.norm(d)
d /= dist
# Sample a direction on the emitter
sample = [0.1, 0.5]
ds, res = emitter.sample_direction(it, sample)
assert ds.time == it.time
assert ds.pdf == 1.0
assert ds.delta
assert ek.allclose(ds.d, d)
# Evalutate the spectrum
spec = spectrum.eval(it) / (dist**2)
assert ek.allclose(res, spec)
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 test04_direction_sample_construction_single(variant_scalar_rgb):
from mitsuba.render import Interaction3f, DirectionSample3f, SurfaceInteraction3f
# Default constructor
record = DirectionSample3f()
record.p = [1, 2, 3]
record.n = [4, 5, 6]
record.uv = [7, 8]
record.d = [0, 42, -1]
record.pdf = 0.002
record.dist = 0.13
assert ek.allclose(record.d, [0, 42, -1])
assert str(record) == """DirectionSample3f[
p = [1, 2, 3],
n = [4, 5, 6],
uv = [7, 8],
time = 0,
pdf = 0.002,
delta = 0,
object = nullptr,
d = [0, 42, -1],
dist = 0.13
]"""
# Construct from two interactions: ds.d should start from the reference its.
its = SurfaceInteraction3f.zero()
its.p = [20, 3, 40.02]
its.t = 1
ref = Interaction3f.zero()
ref.p = [1.6, -2, 35]
record = DirectionSample3f(its, ref)
d = (its.p - ref.p) / ek.norm(its.p - ref.p)
assert ek.allclose(record.d, d)
def test01_point_sample_ray(variant_packet_spectral, spectrum_key):
# Check the correctness of the sample_ray() method
from mitsuba.core import Vector3f, warp, sample_shifted
from mitsuba.render import SurfaceInteraction3f
emitter_pos = [10, -1, 2]
emitter, spectrum = create_emitter_and_spectrum(emitter_pos, spectrum_key)
time = 0.5
wavelength_sample = [0.5, 0.33, 0.1]
dir_sample = [[0.4, 0.5, 0.3], [0.1, 0.4, 0.9]]
pos_sample = dir_sample # not being used anyway
# Sample a ray (position, direction, wavelengths) on the emitter
ray, res = emitter.sample_ray(time, wavelength_sample, pos_sample,
dir_sample)
# Sample wavelengths on the spectrum
it = SurfaceInteraction3f.zero(3)
wav, spec = spectrum.sample_spectrum(it, sample_shifted(wavelength_sample))
assert ek.allclose(res, spec * 4 * ek.pi)
assert ek.allclose(ray.time, time)
assert ek.allclose(ray.wavelengths, wav)
assert ek.allclose(ray.d, warp.square_to_uniform_sphere(dir_sample))
assert ek.allclose(ray.o, Vector3f(emitter_pos))
def test03_sample_ray(variant_packet_spectral, spectrum_key):
# Check the correctness of the sample_ray() method
from mitsuba.core import warp, Frame3f, sample_shifted
from mitsuba.render import SurfaceInteraction3f
shape, spectrum = create_emitter_and_spectrum(spectrum_key)
emitter = shape.emitter()
time = 0.5
wavelength_sample = [0.5, 0.33, 0.1]
pos_sample = [[0.2, 0.1, 0.2], [0.6, 0.9, 0.2]]
dir_sample = [[0.4, 0.5, 0.3], [0.1, 0.4, 0.9]]
# Sample a ray (position, direction, wavelengths) on the emitter
ray, res = emitter.sample_ray(time, wavelength_sample, pos_sample,
dir_sample)
# Sample wavelengths on the spectrum
it = SurfaceInteraction3f.zero(3)
wav, spec = spectrum.sample_spectrum(it, sample_shifted(wavelength_sample))
# Sample a position on the shape
ps = shape.sample_position(time, pos_sample)
assert ek.allclose(res, spec * shape.surface_area() * ek.pi)
assert ek.allclose(ray.time, time)
assert ek.allclose(ray.wavelengths, wav)
assert ek.allclose(ray.o, ps.p)
assert ek.allclose(
ray.d,
Frame3f(ps.n).to_world(warp.square_to_cosine_hemisphere(dir_sample)))
def test_sample_direction(variant_scalar_spectral, spectrum_key, direction):
# Check correctness of sample_direction() and pdf_direction() methods
from mitsuba.render import SurfaceInteraction3f
from mitsuba.core import Vector3f
direction = Vector3f(direction)
emitter = make_emitter(direction, spectrum_key)
spectrum = make_spectrum(spectrum_key)
it = SurfaceInteraction3f.zero()
# Some position inside the unit sphere (i.e. within the emitter's default bounding sphere)
it.p = [-0.5, 0.3, -0.1]
it.time = 1.0
# Sample direction
samples = [0.85, 0.13]
ds, res = emitter.sample_direction(it, samples)
# Direction should point *towards* the illuminated direction
assert ek.allclose(ds.d, -direction / ek.norm(direction))
assert ek.allclose(ds.pdf, 1.)
assert ek.allclose(emitter.pdf_direction(it, ds), 0.)
assert ek.allclose(ds.time, it.time)
# Check spectrum (no attenuation vs distance)
spec = spectrum.eval(it)
assert ek.allclose(res, spec)
def test04_sample_direction(variant_packet_spectral, spectrum_key):
# Check the correctness of the sample_direction() and pdf_direction() methods
from mitsuba.render import SurfaceInteraction3f
shape, spectrum = create_emitter_and_spectrum(spectrum_key)
emitter = shape.emitter()
# Direction sampling is conditioned on a sampled position
it = SurfaceInteraction3f.zero(3)
it.p = [[0.2, 0.1, 0.2], [0.6, -0.9, 0.2], [0.4, 0.9,
-0.2]] # Some positions
it.time = 1.0
# Sample direction on the emitter
samples = [[0.4, 0.5, 0.3], [0.1, 0.4, 0.9]]
ds, res = emitter.sample_direction(it, samples)
# Sample direction on the shape
shape_ds = shape.sample_direction(it, samples)
assert ek.allclose(ds.pdf, shape_ds.pdf)
assert ek.allclose(ds.pdf, emitter.pdf_direction(it, ds))
assert ek.allclose(ds.d, shape_ds.d)
assert ek.allclose(ds.time, it.time)
# Evalutate the spectrum (divide by the pdf)
spec = spectrum.eval(it) / ds.pdf
assert ek.allclose(res, spec)
def test03_sample_direction(variant_packet_spectral):
# Check the correctness of the sample_direction() and pdf_direction() methods
from mitsuba.core import warp
from mitsuba.core.math import InvFourPi
from mitsuba.render import SurfaceInteraction3f
emitter, spectrum = create_emitter_and_spectrum()
it = SurfaceInteraction3f.zero(3)
# Some positions inside the unit sphere
it.p = [[-0.5, 0.3, -0.1], [0.8, -0.3, -0.2], [-0.2, 0.6, -0.6]]
it.time = 1.0
# Sample direction on the emitter
samples = [[0.4, 0.5, 0.3], [0.1, 0.4, 0.9]]
ds, res = emitter.sample_direction(it, samples)
assert ek.allclose(ds.pdf, InvFourPi)
assert ek.allclose(ds.d, warp.square_to_uniform_sphere(samples))
assert ek.allclose(emitter.pdf_direction(it, ds), InvFourPi)
assert ek.allclose(ds.time, it.time)
# Evaluate the spectrum (divide by the pdf)
spec = spectrum.eval(it) / warp.square_to_uniform_sphere_pdf(ds.d)
assert ek.allclose(res, spec)
def test01_eval(variant_packet_spectral, spectrum_key):
# Check the correctness of the eval() method
from mitsuba.core import warp
from mitsuba.core.math import InvFourPi
from mitsuba.render import SurfaceInteraction3f
emitter, spectrum = create_emitter_and_spectrum(spectrum_key)
it = SurfaceInteraction3f.zero()
assert ek.allclose(emitter.eval(it), spectrum.eval(it))
def test_eval(variant_packet_spectral, spectrum_key, lookat, cutoff_angle):
# Check the correctness of the eval() method
from mitsuba.render import SurfaceInteraction3f
emitter, spectrum = create_emitter_and_spectrum(lookat, cutoff_angle,
spectrum_key)
# Check that incident direction in the illuminated direction is zero (because hitting a delta light is impossible)
it = SurfaceInteraction3f.zero(3)
it.wi = [0, 1, 0]
assert ek.allclose(emitter.eval(it), 0.)
def test_sample_direction(variant_scalar_spectral, spectrum_key, it_pos,
wavelength_sample, cutoff_angle, lookat):
# Check the correctness of the sample_direction() method
import math
from mitsuba.core import sample_shifted, Transform4f
from mitsuba.render import SurfaceInteraction3f
cutoff_angle_rad = math.radians(cutoff_angle)
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))
# Create a surface iteration
it = SurfaceInteraction3f.zero()
it.p = it_pos
it.time = eval_t
# Sample a wavelength from spectrum
wav, spec = spectrum.sample(it, sample_shifted(wavelength_sample))
it.wavelengths = wav
# Direction from the position to the point emitter
d = -it.p + lookat["pos"]
dist = ek.norm(d)
d /= dist
# Calculate angle between lookat direction and ray direction
angle = ek.acos((trafo.inverse().transform_vector(-d))[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 direction from the emitter
ds, res = emitter.sample_direction(it, [0, 0])
# Evalutate the spectrum
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 ds.time == it.time
assert ds.pdf == 1.0
assert ds.delta
assert ek.allclose(ds.d, d)
assert ek.allclose(res, spec / (dist**2))
def test02_eval(variant_packet_spectral, spectrum_key):
# Check that eval() return the same values as the 'radiance' spectrum
from mitsuba.render import SurfaceInteraction3f
shape, spectrum = create_emitter_and_spectrum(spectrum_key)
emitter = shape.emitter()
it = SurfaceInteraction3f.zero(3)
assert ek.allclose(emitter.eval(it), spectrum.eval(it))
# Check that eval return 0.0 when direction points inside the shape
it.wi = ek.normalize([0.2, 0.2, -0.5])
assert ek.allclose(emitter.eval(it), 0.0)
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 test_sample_ray(variant_scalar_spectral, direction, spectrum_key):
from mitsuba.core import Vector2f, Vector3f, sample_shifted
from mitsuba.render import SurfaceInteraction3f
emitter = make_emitter(direction=direction, spectrum_key=spectrum_key)
spectrum = make_spectrum(spectrum_key)
direction = Vector3f(direction)
time = 1.0
for wavelength_sample, spatial_sample, directional_sample in zip(
cycle([0.3, 0.7]),
[
[0.85, 0.13],
[0.16, 0.50],
[0.00, 1.00],
[0.32, 0.87],
[0.16, 0.44],
[0.17, 0.44],
[0.22, 0.81],
[0.12, 0.82],
[0.99, 0.42],
[0.72, 0.40],
[0.01, 0.61],
],
cycle([[0.3, 0.2]])
):
ray, _ = emitter.sample_ray(
time, wavelength_sample, spatial_sample, directional_sample)
# Check that ray direction is what is expected
assert ek.allclose(ray.d, direction / ek.norm(direction))
# Check that ray origin is outside of bounding sphere
# Bounding sphere is centered at world origin and has radius 1 without scene
assert ek.norm(ray.o) >= 1.
# Check that passed irradiance spectrum is used for wavelength sampling
it = SurfaceInteraction3f.zero()
wav, spec = spectrum.sample_spectrum(
it, sample_shifted(wavelength_sample))
assert ek.allclose(ray.wavelengths, wav)
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)
# Create a texture with the reference displacement map
disp_tex_1 = xml.load_dict({
"type" : "bitmap",
"filename": "diffuser_surface_1.jpg",
"to_uv" : ScalarTransform4f.scale([1, -1, 1]) # texture is upside-down
}).expand()[0]
# Create a texture with another displacement map
disp_tex_2 = xml.load_dict({
"type" : "bitmap",
"filename": "diffuser_surface_2.jpg",
"to_uv" : ScalarTransform4f.scale([1, -1, 1]) # texture is upside-down
}).expand()[0]
# Create a fake surface interaction with an entry per vertex on the mesh
mesh_si = SurfaceInteraction3f.zero(vertex_count)
mesh_si.uv = ravel(params['grid_mesh.vertex_texcoords_buf'], dim=2)
# Evaluate the displacement map for the entire mesh
disp_tex_diffuser_1 = disp_tex_1.eval_1(mesh_si)
disp_tex_diffuser_2 = disp_tex_2.eval_1(mesh_si)
# Apply displacement to mesh vertex positions and update scene (e.g. OptiX BVH)
def apply_displacement(disp, amplitude = 0.05):
new_positions = disp.eval_1(mesh_si) * normals_initial * amplitude + positions_initial
unravel(new_positions, params['grid_mesh.vertex_positions_buf'])
params.set_dirty('grid_mesh.vertex_positions_buf')
params.update()
# Change amp to adjust the magnitude of displacement
amp = 0.1
def pdf_functor(w, *args):
plugin = instantiate(args)
si = SurfaceInteraction3f.zero(ek.slices(w))
si.wavelengths = w
return plugin.pdf(si)[0]
def sample_functor(sample, *args):
plugin = instantiate(args)
si = SurfaceInteraction3f.zero(ek.slices(sample))
wavelength, weight = plugin.sample(si, sample_shifted(sample[0]))
return Vector1f(wavelength[0])
def make_context(n):
si = SurfaceInteraction3f.zero(n)
si.wi = wi
ek.set_slices(si.wi, n)
si.wavelengths = []
return (si, ctx)