novaphy.ParticleState
Structure-of-arrays particle storage used by the
SolverPBF pipeline (and by stand-alone
PBFSolver users). Holds fluid particle positions, velocities, densities,
and PBF Lagrange multipliers, plus optional per-particle mass and rest-
density fields for multi-material setups.
Methods
| Method |
Description |
init(initial_positions, initial_velocity=[0, 0, 0]) |
Initialize the buffers from a list of starting positions and a uniform initial velocity. |
clear() |
Drop all particle data. |
Properties
| Property |
Description |
num_particles |
Number of fluid particles. |
positions |
List of particle world-frame positions [m]. |
velocities |
List of particle world-frame velocities [m/s]. |
densities |
Per-particle density estimate [kg/m³]. |
lambdas |
PBF density-constraint Lagrange multipliers retained after a solver step. |
particle_masses |
Per-particle mass [kg]. Empty when a single-material init was used. |
rest_densities |
Per-particle rest density ρ₀ [kg/m³]. Empty for single-material setups. |
particle_world |
Per-particle world index (-1 denotes the global world). |
Example
import numpy as np
import novaphy
ps = novaphy.ParticleState()
positions = np.array(
[[i * 0.05, 1.0, 0.0] for i in range(64)], dtype=np.float32
)
ps.init(positions, initial_velocity=np.array([0, 0, 0], dtype=np.float32))
print(ps.num_particles, "particles initialized")
print("first density:", ps.densities[0] if ps.num_particles else "n/a")
Notes
- The ordering between
positions / velocities / densities is
identical — index i always refers to the same particle across all
channels.
lambdas is owned by the solver. Python can inspect the copied vector after
or between complete solver steps; the public step call does not expose
callbacks between its internal iterations.
See Also