Models and Utils

Python: phynexis.parsim Headers: src/parsim/models/*.hpp, src/parsim/utils/*.hpp

Contact models, node generation utilities, and spatial indexing helpers.

RepulsionModel

Base class for contact repulsion models.

Methods

Method	Returns	Description
name()	str	Model name
clone()	RepulsionModel*	Deep copy

LinearRepulsionModel

Simple linear spring repulsion.

Constructors

Signature	Description
LinearRepulsionModel()	Default stiffness.
LinearRepulsionModel(stiffness)	Specify stiffness.

Methods

Method	Returns	Description
stiffness()	float	Current stiffness
set_stiffness(v)	—	Set stiffness

Example:

import phynexis
pm = phynexis.parsim

model = pm.LinearRepulsionModel(1000.0)
print(model.stiffness())  # 1000.0
print(model.name())       # "LinearRepulsionModel"

clone = model.clone()
print(type(clone).__name__)  # LinearRepulsionModel

RepulsionModelFactory

Factory for creating repulsion models by name.

Static Methods

Method	Returns	Description
create_model(name)	RepulsionModel*	Create model by name
get_available_models()	list[str]	List registered model names
is_registered(name)	bool	Check if name is registered
print_info()	—	Print factory info

Example:

print(pm.RepulsionModelFactory.get_available_models())
model = pm.RepulsionModelFactory.create_model("LinearRepulsionModel")

NodeGenerator

Generates node property sets from field samplers.

Constructors

Signature	Description
NodeGenerator()	Empty generator.

Methods

Method	Description
add_field(slot, sampler)	Add a field slot with sampler
add_field(name, sampler)	Add Vec3 field by name (spatial sampler)
add_field(name, dist)	Add scalar field by name (distribution)
add_field(name, generator)	Add field by callable (double/Vec3/JSON)
erase_field(name)	Remove a field slot
contains(name)	Check if slot exists
slots()	Get all slots
num_slots()	Number of slots
slot(i) / slot(name)	Get slot by index or name
generate_one()	Generate one node's properties (JSON)
generate(count)	Generate count nodes (list of JSON)
clear()	Remove all slots
print_slots()	Print slot info to stderr

Example:

import phynexis
pm = phynexis.parsim
U = phynexis.utils

gen = pm.NodeGenerator()

# Add a scalar field with fixed value
gen.add_field("radius", lambda: 0.5)

# Add a Vec3 field with random position
sampler = U.sampling.spatial.UniformBoxSampler(
    U.Vec3d(0, 0, 0), U.Vec3d(1, 1, 1)
)
gen.add_field("pos", sampler)

# Generate 3 nodes
nodes = gen.generate(3)
print(len(nodes))  # 3
print(nodes[0])    # {'radius': 0.5, 'pos': [x, y, z]}

FieldSampler

Factory for creating field samplers used by NodeGenerator.

Static Methods

Method	Returns	Description
make_scalar(dist)	FieldSampler	From distribution
make_scalar(generator)	FieldSampler	From callable () -> double
make_scalar(value)	FieldSampler	From constant value
make_vec3(sampler)	FieldSampler	From spatial sampler
make_vec3(generator)	FieldSampler	From callable () -> Vec3d
make_vec4(sampler)	FieldSampler	From orientation sampler
make_json(generator)	FieldSampler	From callable () -> dict

Node Property Utils

Free functions for node property manipulation.

apply_density(view, density)

Applies density to node mass/inertia fields.

assign_shape(view, shape_id)

Assigns a shape ID to nodes.

update_node_bounds(nodes, skin_factor=0.05, margin_factor=0.1)

Updates AABB bounds for all nodes.

Example:

ns = pm.NodeSet()
# ... setup and initialize ...

pm.update_node_bounds(ns, 0.05, 0.1)

SpatialIndex / UniformGridIndex

See simulator for full documentation.

Quick example:

idx = pm.UniformGridIndex()
config = idx.config()
config.min_bound = U.Vec3d(0, 0, 0)
config.max_bound = U.Vec3d(10, 10, 10)
config.grid_size = U.Vec3d(1, 1, 1)

idx.build(ns)
result = idx.query(U.Vec3d(5, 5, 5), 2.0)
print(result)  # list of node indices within radius 2.0

Known Issues

NodeGenerator.generate() returns list[dict] not VecX[json]

The binding wraps VecX<json> to py::list for compatibility.

Status: noted