def test02_sample_ray(variant_packet_spectral, origin, direction):
# Check the correctness of the sample_ray() method
from mitsuba.core import sample_shifted, sample_rgb_spectrum
camera = create_camera(origin, direction)
time = 0.5
wav_sample = [0.5, 0.33, 0.1]
pos_sample = [[0.2, 0.1, 0.2], [0.6, 0.9, 0.2]]
aperture_sample = 0 # Not being used
ray, spec_weight = camera.sample_ray(time, wav_sample, pos_sample,
aperture_sample)
# Importance sample wavelength and weight
wav, spec = sample_rgb_spectrum(sample_shifted(wav_sample))
assert ek.allclose(ray.wavelengths, wav)
assert ek.allclose(spec_weight, spec)
assert ek.allclose(ray.time, time)
assert ek.allclose(ray.o, origin)
# Check that a [0.5, 0.5] position_sample generates a ray
# that points in the camera direction
ray, _ = camera.sample_ray(0, 0, [0.5, 0.5], 0)
assert ek.allclose(ray.d, direction, atol=1e-7)
def test02_sample_ray(variant_packet_spectral, origin, direction, aperture_rad,
focus_dist):
# Check the correctness of the sample_ray() method
from mitsuba.core import sample_shifted, sample_rgb_spectrum, warp, Vector3f, Transform4f
cam = create_camera(origin,
direction,
aperture=aperture_rad,
focus_dist=focus_dist)
time = 0.5
wav_sample = [0.5, 0.33, 0.1]
pos_sample = [[0.2, 0.1, 0.2], [0.6, 0.9, 0.2]]
aperture_sample = [0.5, 0.5]
ray, spec_weight = cam.sample_ray(time, wav_sample, pos_sample,
aperture_sample)
# Importance sample wavelength and weight
wav, spec = sample_rgb_spectrum(sample_shifted(wav_sample))
assert ek.allclose(ray.wavelengths, wav)
assert ek.allclose(spec_weight, spec)
assert ek.allclose(ray.time, time)
assert ek.allclose(ray.o, origin)
# Check that a [0.5, 0.5] position_sample and [0.5, 0.5] aperture_sample
# generates a ray that points in the camera direction
ray, _ = cam.sample_ray(0, 0, [0.5, 0.5], [0.5, 0.5])
assert ek.allclose(ray.d, direction, atol=1e-7)
# ----------------------------------------
# Check correctness of aperture sampling
pos_sample = [0.5, 0.5]
aperture_sample = [[0.9, 0.4, 0.2], [0.6, 0.9, 0.7]]
ray, _ = cam.sample_ray(time, wav_sample, pos_sample, aperture_sample)
ray_centered, _ = cam.sample_ray(time, wav_sample, pos_sample, [0.5, 0.5])
trafo = Transform4f(cam.world_transform().eval(time).matrix.numpy())
tmp = warp.square_to_uniform_disk_concentric(aperture_sample)
aperture_v = trafo.transform_vector(aperture_rad *
Vector3f(tmp.x, tmp.y, 0))
# NOTE: here we assume near_clip = 1.0
assert ek.allclose(ray.o, ray_centered.o + aperture_v)
assert ek.allclose(ray.d,
ek.normalize(ray_centered.d * focus_dist - aperture_v))
def test03_sample_ray_differential(variant_packet_spectral, origin, direction):
# Check the correctness of the sample_ray_differential() method
from mitsuba.core import sample_shifted, sample_rgb_spectrum
camera = create_camera(origin, direction)
time = 0.5
wav_sample = [0.5, 0.33, 0.1]
pos_sample = [[0.2, 0.1, 0.2], [0.6, 0.9, 0.2]]
ray, spec_weight = camera.sample_ray_differential(time, wav_sample,
pos_sample, 0)
# Importance sample wavelength and weight
wav, spec = sample_rgb_spectrum(sample_shifted(wav_sample))
assert ek.allclose(ray.wavelengths, wav)
assert ek.allclose(spec_weight, spec)
assert ek.allclose(ray.time, time)
assert ek.allclose(ray.o, origin)
# Check that the derivatives are orthogonal
assert ek.allclose(ek.dot(ray.d_x - ray.d, ray.d_y - ray.d), 0, atol=1e-7)
# Check that a [0.5, 0.5] position_sample generates a ray
# that points in the camera direction
ray_center, _ = camera.sample_ray_differential(0, 0, [0.5, 0.5], 0)
assert ek.allclose(ray_center.d, direction, atol=1e-7)
# Check correctness of the ray derivatives
# Deltas in screen space
dx = 1.0 / camera.film().crop_size().x
dy = 1.0 / camera.film().crop_size().y
# Sample the rays by offsetting the position_sample with the deltas
ray_dx, _ = camera.sample_ray_differential(0, 0, [0.5 + dx, 0.5], 0)
ray_dy, _ = camera.sample_ray_differential(0, 0, [0.5, 0.5 + dy], 0)
assert ek.allclose(ray_dx.d, ray_center.d_x)
assert ek.allclose(ray_dy.d, ray_center.d_y)
def spot_check(sample, expected_wav, expected_weight):
wav, weight = sample_rgb_spectrum(sample)
pdf = pdf_rgb_spectrum(wav)
assert ek.allclose(wav, expected_wav)
assert ek.allclose(weight, expected_weight)
assert ek.allclose(pdf, 1.0 / weight)
def test03_sample_ray_diff(variant_packet_spectral, origin, direction,
aperture_rad, focus_dist):
# Check the correctness of the sample_ray_differential() method
from mitsuba.core import sample_shifted, sample_rgb_spectrum, warp, Vector3f, Transform4f
cam = create_camera(origin,
direction,
aperture=aperture_rad,
focus_dist=focus_dist)
time = 0.5
wav_sample = [0.5, 0.33, 0.1]
pos_sample = [[0.2, 0.1, 0.2], [0.6, 0.9, 0.2]]
aperture_sample = [0.5, 0.5]
ray, spec_weight = cam.sample_ray_differential(time, wav_sample,
pos_sample, aperture_sample)
# Importance sample wavelength and weight
wav, spec = sample_rgb_spectrum(sample_shifted(wav_sample))
assert ek.allclose(ray.wavelengths, wav)
assert ek.allclose(spec_weight, spec)
assert ek.allclose(ray.time, time)
assert ek.allclose(ray.o, origin)
# ----------------------------------------_
# Check that the derivatives are orthogonal
assert ek.allclose(ek.dot(ray.d_x - ray.d, ray.d_y - ray.d), 0, atol=1e-7)
# Check that a [0.5, 0.5] position_sample and [0.5, 0.5] aperture_sample
# generates a ray that points in the camera direction
ray_center, _ = cam.sample_ray_differential(0, 0, [0.5, 0.5], [0.5, 0.5])
assert ek.allclose(ray_center.d, direction, atol=1e-7)
# ----------------------------------------
# Check correctness of the ray derivatives
aperture_sample = [[0.9, 0.4, 0.2], [0.6, 0.9, 0.7]]
ray_center, _ = cam.sample_ray_differential(0, 0, [0.5, 0.5],
aperture_sample)
# Deltas in screen space
dx = 1.0 / cam.film().crop_size().x
dy = 1.0 / cam.film().crop_size().y
# Sample the rays by offsetting the position_sample with the deltas (aperture centered)
ray_dx, _ = cam.sample_ray_differential(0, 0, [0.5 + dx, 0.5],
aperture_sample)
ray_dy, _ = cam.sample_ray_differential(0, 0, [0.5, 0.5 + dy],
aperture_sample)
assert ek.allclose(ray_dx.d, ray_center.d_x)
assert ek.allclose(ray_dy.d, ray_center.d_y)
# --------------------------------------
# Check correctness of aperture sampling
pos_sample = [0.5, 0.5]
aperture_sample = [[0.9, 0.4, 0.2], [0.6, 0.9, 0.7]]
ray, _ = cam.sample_ray(time, wav_sample, pos_sample, aperture_sample)
ray_centered, _ = cam.sample_ray(time, wav_sample, pos_sample, [0.5, 0.5])
trafo = Transform4f(cam.world_transform().eval(time).matrix.numpy())
tmp = warp.square_to_uniform_disk_concentric(aperture_sample)
aperture_v = trafo.transform_vector(aperture_rad *
Vector3f(tmp.x, tmp.y, 0))
# NOTE: here we assume near_clip = 1.0
assert ek.allclose(ray.o, ray_centered.o + aperture_v)
assert ek.allclose(ray.d,
ek.normalize(ray_centered.d * focus_dist - aperture_v))