def test_properties_dict(self):
world = World()
world.add(Fluid(Domain([16, 16])), physics=IncompressibleFlow())
world.add(Inflow(Sphere((8, 8), radius=4)))
# world.add(ConstantDensity(box[0:2, 6:10], 1.0))
world.add(Fan(Sphere((10, 8), 5), [-1, 0]))
struct.properties_dict(world.state)
def simulate(centers):
world = World()
fluid = world.add(Fluid(Domain([5, 4], boundaries=CLOSED, box=AABox(0, [40, 32])),
buoyancy_factor=0.1,
batch_size=centers.shape[0]),
physics=IncompressibleFlow(pressure_solver=SparseCG(max_iterations=3)))
world.add(Inflow(Sphere(center=centers, radius=3), rate=0.2))
world.add(Fan(Sphere(center=centers, radius=5), acceleration=[1.0, 0]))
world.step(dt=1.5)
world.step(dt=1.5)
world.step(dt=1.5)
print()
return fluid.density.data[0, ...], fluid.velocity.unstack()[0].data[0, ...], fluid.velocity.unstack()[1].data[0, ...]
def simulate(centers):
world = World()
fluid = world.add(Fluid(Domain(x=5, y=4, bounds=Box(0, [40, 32])),
buoyancy_factor=0.1,
batch_size=centers.shape[0]),
physics=IncompressibleFlow())
world.add(Inflow(Sphere(center=centers, radius=3), rate=0.2))
world.add(Fan(Sphere(center=centers, radius=5), acceleration=[1.0, 0]))
world.step(dt=1.5)
world.step(dt=1.5)
world.step(dt=1.5)
assert not math.close(fluid.density.values, 0)
print()
return fluid.density.values.batch[0], fluid.velocity.values.batch[0]
def points(self,
points: Tensor or Number or tuple or list,
values: Tensor or Number = None,
radius: Tensor or float or int or None = None,
extrapolation: math.Extrapolation = math.extrapolation.ZERO,
color: str or Tensor or tuple or list or None = None) -> PointCloud:
"""
Create a `phi.field.PointCloud` from the given `points`.
The created field has no channel dimensions and all points carry the value `1`.
Args:
points: point locations in physical units
values: (optional) values of the particles, defaults to 1.
radius: (optional) size of the particles
extrapolation: (optional) extrapolation to use, defaults to extrapolation.ZERO
color: (optional) color used when plotting the points
Returns:
`phi.field.PointCloud` object
"""
extrapolation = extrapolation if isinstance(extrapolation, math.Extrapolation) else self.boundaries[extrapolation]
if radius is None:
radius = math.mean(self.bounds.size) * 0.005
# --- Parse points: tuple / list ---
if isinstance(points, (tuple, list)):
if len(points) == 0: # no points
points = math.zeros(instance(points=0), channel(vector=1))
elif isinstance(points[0], Number): # single point
points = math.tensor([points], instance('points'), channel('vector'))
else:
points = math.tensor(points, instance('points'), channel('vector'))
elements = Sphere(points, radius)
if values is None:
values = math.tensor(1.)
return PointCloud(elements, values, extrapolation, add_overlapping=False, bounds=self.bounds, color=color)
def tensor_as_field(t: Tensor):
"""
Interpret a `Tensor` as a `CenteredGrid` or `PointCloud` depending on its dimensions.
Unlike the `CenteredGrid` constructor, this function will have the values sampled at integer points for each spatial dimension.
Args:
t: `Tensor` with either `spatial` or `instance` dimensions.
Returns:
`CenteredGrid` or `PointCloud`
"""
if spatial(t):
assert not instance(
t
), f"Cannot interpret tensor as Field because it has both spatial and instance dimensions: {t.shape}"
bounds = Box(-0.5, math.wrap(spatial(t), channel('vector')) - 0.5)
return CenteredGrid(t, 0, bounds=bounds)
if instance(t):
assert not spatial(
t
), f"Cannot interpret tensor as Field because it has both spatial and instance dimensions: {t.shape}"
assert 'vector' in t.shape, f"Cannot interpret tensor as PointCloud because it has not vector dimension."
point_count = instance(t).volume
bounds = data_bounds(t)
radius = math.vec_length(
bounds.size) / (1 + point_count**(1 / t.vector.size))
return PointCloud(Sphere(t, radius=radius))
def respect_boundaries(particles: PointCloud,
domain: Domain,
not_accessible: list,
offset: float = 0.5) -> PointCloud:
"""
Enforces boundary conditions by correcting possible errors of the advection step and shifting particles out of
obstacles or back into the domain.
Args:
particles: PointCloud holding particle positions as elements
domain: Domain for which any particles outside should get shifted inwards
not_accessible: List of Obstacle or Geometry objects where any particles inside should get shifted outwards
offset: Minimum distance between particles and domain boundary / obstacle surface after particles have been shifted.
Returns:
PointCloud where all particles are inside the domain / outside of obstacles.
"""
new_positions = particles.elements.center
for obj in not_accessible:
if isinstance(obj, Obstacle):
obj = obj.geometry
new_positions = obj.push(new_positions, shift_amount=offset)
new_positions = (~domain.bounds).push(new_positions, shift_amount=offset)
return particles.with_(
elements=Sphere(new_positions,
math.mean(particles.bounds.size) * 0.005))
def _test_make_incompressible(self, grid_type: type,
extrapolation: math.Extrapolation,
**batch_dims):
result = None
for i, backend in enumerate(BACKENDS):
with backend:
smoke = CenteredGrid(Sphere(
center=(math.random_uniform(batch(**batch_dims)) * 100,
10),
radius=5),
extrapolation,
x=16,
y=20,
bounds=Box[0:100, 0:100])
velocity = grid_type(0,
extrapolation,
x=16,
y=20,
bounds=Box[0:100, 0:100])
for _ in range(2):
velocity += smoke * (0, 0.1) @ velocity
velocity, _ = fluid.make_incompressible(velocity)
math.assert_close(divergence(velocity).values,
0,
abs_tolerance=2e-5)
if result is None:
result = velocity
else:
field.assert_close(
result,
abs_tolerance=1e-5,
msg=
f"Simulation with {backend} does not match {BACKENDS[:i]}"
)
def test_gradient_batch_independence(self):
session = Session(None) # Used to run the TensorFlow graph
world = World()
fluid = world.add(Fluid(Domain([40, 32], boundaries=CLOSED), buoyancy_factor=0.1, batch_size=2), physics=IncompressibleFlow())
world.add(Inflow(Sphere(center=numpy.array([[5, 4], [5, 8]]), radius=3), rate=0.2))
fluid.velocity = variable(fluid.velocity) # create TensorFlow variable
# fluid.velocity *= 0
initial_state = fluid.state # Remember the state at t=0 for later visualization
session.initialize_variables()
for frame in range(3):
world.step(dt=1.5)
target = session.run(fluid.density).data[0, ...]
loss = tf.nn.l2_loss(fluid.density.data[1, ...] - target)
self_loss = tf.nn.l2_loss(fluid.density.data[0, ...] - target)
# loss = self_loss
optim = tf.train.GradientDescentOptimizer(learning_rate=0.2).minimize(loss)
session.initialize_variables()
for optim_step in range(3):
_, loss_value, sl_value = session.run([optim, loss, self_loss])
staggered_velocity = session.run(initial_state.velocity).staggered_tensor()
numpy.testing.assert_equal(staggered_velocity[0, ...], 0)
assert numpy.all(~numpy.isnan(staggered_velocity))
def test_effects(self):
world = World()
fluid = world.add(Fluid(Domain([16, 16])))
fan = world.add(Fan(Sphere((10, 8), 5), [-1, 0]))
obstacle = world.add(Obstacle(box[0:1, 0:1]))
world.step(dt=1)
world.step(dt=0.5)
assert fluid.age == fan.age == obstacle.age == 1.5
def test_effects(self):
world = World()
fluid = world.add(Fluid(Domain(x=16, y=16)), physics=IncompressibleFlow())
fan = world.add(Fan(Sphere((10, 8), 5), [-1, 0]))
obstacle = world.add(Obstacle(Box[0:1, 0:1]))
world.step(dt=1)
world.step(dt=0.5)
assert fluid.age == fan.age == obstacle.age == 1.5
def test_plot_multiple(self):
grid = CenteredGrid(Noise(batch(b=2)), 0, Box[0:1, 0:1], x=50, y=10)
grid2 = CenteredGrid(grid, 0, Box[0:2, 0:1], x=20, y=50)
points = wrap([(.2, .4), (.9, .8)], instance('points'),
channel('vector'))
cloud = PointCloud(Sphere(points, radius=0.1), bounds=Box(0, [1, 1]))
titles = math.wrap([['b=0', 'b=0', 'points'], ['b=1', 'b=1', '']],
spatial('rows,cols'))
self._test_plot(grid, grid2, cloud, row_dims='b', title=titles)
def _test_make_incompressible_batched(self, grid_type):
DOMAIN = Domain(x=16, y=16, boundaries=CLOSED, bounds=Box[0:100, 0:100])
smoke = DOMAIN.scalar_grid(Sphere(center=(math.random_uniform(batch=2) * 100, 10), radius=5))
velocity = DOMAIN.vector_grid(0, grid_type)
for _ in range(2):
velocity += smoke * (0, 0.1) >> velocity
velocity, pressure, _, _ = fluid.make_incompressible(velocity, DOMAIN)
math.assert_close(divergence(velocity).values, 0, abs_tolerance=2e-5)
return velocity.values
def test_smoke_plume(self):
world = World()
world.batch_size = 3
fluid = world.add(Fluid(Domain(x=16, y=16)), physics=IncompressibleFlow())
inflow = world.add(Inflow(Sphere((8, 8), radius=4)))
world.step()
world.step(fluid)
self.assertAlmostEqual(fluid.age, 2.0)
self.assertAlmostEqual(inflow.age, 1.0)
def test_simpleplume(self):
world = World()
world.batch_size = 3
fluid = world.add(Fluid(Domain([16, 16])))
inflow = world.add(Inflow(Sphere((8, 8), radius=4)))
world.step()
world.step(fluid)
self.assertAlmostEqual(fluid.age, 2.0)
self.assertAlmostEqual(inflow.age, 1.0)
def test_convert_point_cloud(self):
loc = math.random_uniform(instance(points=4), channel(vector=2))
val = math.random_normal(instance(points=4), channel(vector=2))
points = PointCloud(Sphere(loc, radius=1), val)
for backend in BACKENDS:
converted = field.convert(points, backend)
self.assertEqual(converted.values.default_backend, backend)
self.assertEqual(converted.elements.center.default_backend,
backend)
self.assertEqual(converted.elements.radius.default_backend,
backend)
def test_overlay(self):
grid = CenteredGrid(Noise(),
extrapolation.ZERO,
x=64,
y=8,
bounds=Box(0, [1, 1]))
points = wrap([(.2, .4), (.9, .8)], instance('points'),
channel('vector'))
cloud = PointCloud(Sphere(points, radius=.1))
self._test_plot(overlay(grid, grid * (0.1, 0.02), cloud),
title='Overlay')
def test_plot_point_cloud_2d_large(self):
spheres = PointCloud(
Sphere(wrap([(2, 4), (9, 8), (7, 8)], instance('points'),
channel('vector')),
radius=1))
cells = PointCloud(
geom.pack_dims(
CenteredGrid(0, 0, x=3, y=3, bounds=Box[4:6, 2:4]).elements,
'x,y', instance('points')))
cloud = field.stack([spheres, cells], instance('stack'))
self._test_plot(cloud)
def test_plot_point_cloud_2d(self):
spheres = PointCloud(
Sphere(wrap([(.2, .4), (.9, .8), (.7, .8)], instance('points'),
channel('vector')),
radius=.1))
cells = PointCloud(
geom.pack_dims(
CenteredGrid(0, 0, x=3, y=3,
bounds=Box[.4:.6, .2:.4]).elements, 'x,y',
instance('points')))
cloud = field.stack([spheres, cells], instance('stack'))
self._test_plot(cloud)
def test_fluid_tf(self):
world = World()
fluid = Fluid(Domain([16, 16]))
world.add(fluid)
world.add(Inflow(Sphere((8, 8), radius=4)))
world.add(Obstacle(box[4:16, 0:8]))
fluid_in = fluid.copied_with(density=placeholder, velocity=placeholder)
fluid_out = world.step(fluid_in)
self.assertIsInstance(fluid_out, Fluid)
session = Session(Scene.create('data', copy_calling_script=False))
fluid = session.run(fluid_out, {fluid_in: fluid})
fluid = session.run(fluid_out, {fluid_in: fluid})
self.assertIsInstance(fluid, Fluid)
def test_plot_vector_3d_batched(self):
sphere = CenteredGrid(SoftGeometryMask(
Sphere(x=.5, y=.5, z=.5, radius=.4)),
x=10,
y=10,
z=10,
bounds=Box(x=1, y=1, z=1)) * (.1, 0, 0)
cylinder = CenteredGrid(geom.infinite_cylinder(
x=16, y=16, inf_dim='z', radius=10),
x=32,
y=32,
z=32) * (0, 0, .1)
self._test_plot(sphere, cylinder)
def test_batched_sphere(self):
moving_sphere = Sphere(center=np.stack(
[np.ones(10), np.linspace(0, 10, 10)], axis=-1),
radius=1)
growing_sphere = Sphere(center=0, radius=np.linspace(0, 10, 10))
# 0D indexing
values = moving_sphere.value_at(np.zeros([10, 2]) + [1, 4])
np.testing.assert_equal(values[:, 0], [0, 0, 0, 1, 1, 0, 0, 0, 0, 0])
values = growing_sphere.value_at(np.zeros([10, 2]) + [0, 4])
np.testing.assert_equal(values[:, 0], [0, 0, 0, 0, 1, 1, 1, 1, 1, 1])
# 1D indexing
values = moving_sphere.value_at(np.zeros([10, 3, 2]) + [1, 4])
np.testing.assert_equal(values.shape, [10, 3, 1])
np.testing.assert_equal(values[:, 0, 0],
[0, 0, 0, 1, 1, 0, 0, 0, 0, 0])
values = growing_sphere.value_at(np.zeros([10, 3, 2]) + [0, 4])
np.testing.assert_equal(values.shape, [10, 3, 1])
np.testing.assert_equal(values[:, 0, 0],
[0, 0, 0, 0, 1, 1, 1, 1, 1, 1])
def test_staggered_grid_sizes_by_extrapolation(self):
s = spatial(x=20, y=10)
for initializer in [0, Noise(vector=2), (0, 1), Sphere((0, 0), 1)]:
g_const = StaggeredGrid(initializer,
extrapolation.ZERO,
resolution=s)
self.assertEqual(g_const.shape,
spatial(x=20, y=10) & channel(vector=2))
self.assertEqual(g_const.values.vector[0].shape, spatial(x=19,
y=10))
g_periodic = StaggeredGrid(initializer,
extrapolation.PERIODIC,
resolution=s)
self.assertEqual(g_periodic.shape,
spatial(x=20, y=10) & channel(vector=2))
self.assertEqual(g_periodic.values.vector[0].shape,
spatial(x=20, y=10))
g_boundary = StaggeredGrid(initializer,
extrapolation.BOUNDARY,
resolution=s)
self.assertEqual(g_boundary.shape,
spatial(x=20, y=10) & channel(vector=2))
self.assertEqual(g_boundary.values.vector[0].shape,
spatial(x=21, y=10))
def test_union_varying(self):
box = Box[0:1, 0:1]
sphere = Sphere((0, 0), radius=1)
union = geom.union(box, sphere)
math.assert_close(union.approximate_signed_distance((1, 1)),
union.approximate_signed_distance((0, -1)), 0)
def test_sphere_constructor_kwargs(self):
s = Sphere(x=0.5, y=2, radius=1.)
self.assertEqual(s.center.shape.get_item_names('vector'), ('x', 'y'))
def test_sphere_volume(self):
sphere = Sphere(math.tensor([(0, 0, 0), (1, 1, 1)], batch('batch'),
channel('vector')),
radius=math.tensor([1, 2], batch('batch')))
math.assert_close(sphere.volume,
[4 / 3 * math.PI, 4 / 3 * 8 * math.PI])
def test_circle_area(self):
sphere = Sphere(math.tensor([(0, 0), (1, 1)], batch('batch'),
channel('vector')),
radius=math.tensor([1, 2], batch('batch')))
math.assert_close(sphere.volume, [math.PI, 4 * math.PI])
def geometry_at(time):
return Sphere([time], radius=5)
def test_properties_dict(self):
world = World()
world.add(Fluid(Domain(x=16, y=16)), physics=IncompressibleFlow())
world.add(Inflow(Sphere((8, 8), radius=4)))
world.add(Fan(Sphere((10, 8), 5), [-1, 0]))
struct.properties_dict(world.state)
def test_effects(self):
world = World()
world.add(Fluid(Domain([16, 16])))
world.add(Fan(Sphere((10, 8), 5), [-1, 0]))
world.step()
world.step()
def elements(self):
return Sphere(self.sample_points, radius=0.0)