Implicit fields

FieldGenerator objects are given to a PointSampler object to be called on all the sampled points.

Example

import implicitlab as IL

sampler = PointSampler(
    geometry, # some loaded geometry
    IL.sampling_strategy.UniformBox(geometry), # the sampling strategy
    IL.fields.Occupancy(geometry, v_in=-1, v_out=1, v_on=-1) # the field to compute
)
points, field_values = sampler.sampler(10_000) 

This example wil sample 10k points uniformly in a bounding box around the geometry object. It returns the points and an occupancy value for each point.

Available fields

Distance(geom, signed=True, square=False)

summary

Parameters:

Name	Type	Description	Default
geom	Mesh	description	required
signed	bool	description. Defaults to True.	True
square	bool	description. Defaults to False.	False

Raises:

Type	Description
UnsupportedGeometryFormat	description

Occupancy(geom, v_in, v_out, v_on)

summary

Parameters:

Name	Type	Description	Default
geom	Mesh	description	required
v_in	float	description	required
v_out	float	description	required
v_on	float	description	required

Raises:

Type	Description
UnsupportedGeometryFormat	description

Returns:

Name	Type	Description
_type_		description

WindingNumber(geom)

summary

Parameters:

Name	Type	Description	Default
geom	Mesh	description	required

Raises:

Type	Description
UnsupportedGeometryFormat	description

Returns:

Name	Type	Description
_type_		description

References

• Fast winding numbers for soups and clouds, Barill et al., 2018
• https://libigl.github.io/libigl-python-bindings/igl_docs/#fast_winding_number_for_points

Nearest(geom)

summary

Parameters:

Name	Type	Description	Default
geom	Mesh	description	required

Raises:

Type	Description
UnsupportedGeometryFormat	description

Returns:

Name	Type	Description
_type_		description

Constant(value)

Bases: FieldGenerator

summary

Parameters:

Name	Type	Description	Default
value	float	description	required

compute_on(query)

summary

Note

Defining this function is optional. By default, compute_on(query) returns the value of compute(query). Since values of a field are sometimes known for query points on the geometry (for instance: a distance field has value 0 on the surface), it can be useful to avoid the field computation and overwrite this function.

Parameters:

Name	Type	Description	Default
query	ndarray	the query points	required

Returns:

Type	Description
ndarray	np.ndarray: the value of the field at each query point.

CustomFunction(fun, fun_on=None)

Bases: FieldGenerator

summary

Parameters:

Name	Type	Description	Default
fun	Callable	description	required
fun_on	Callable	description. Defaults to None.	None

Make your custom field

The list of possible fields can be expanded by writing a custom class that inherits from the base abstract class FieldGenerator.

FieldGenerator

Bases: ABC

Base class for an implicit field.

compute(query) abstractmethod

summary

Parameters:

Name	Type	Description	Default
query	ndarray	the query points	required

Returns:

Type	Description
ndarray	np.ndarray: the value of the field at each query point

compute_on(query)

summary

Note

Defining this function is optional. By default, compute_on(query) returns the value of compute(query). Since values of a field are sometimes known for query points on the geometry (for instance: a distance field has value 0 on the surface), it can be useful to avoid the field computation and overwrite this function.

Parameters:

Name	Type	Description	Default
query	ndarray	the query points	required

Returns:

Type	Description
ndarray	np.ndarray: the value of the field at each query point.

The custom class only needs to define the compute method. Additionnally, the compute_on method can be provided.