novaphy.solvers

Newton-aligned novaphy.solvers namespace. Solver classes, configuration objects, and solver-metadata enums live exclusively here; there is no novaphy.SolverXXX top-level shortcut.

import novaphy
solver = novaphy.solvers.SolverSemiImplicit(model)
pipeline = novaphy.CollisionPipeline(model)
contacts = pipeline.contacts()
pipeline.collide(state_in, contacts)
solver.step(state_in, state_out, control, contacts, dt)

All solvers share the contract:

solver.step(state_in: SimState, state_out: SimState,
            control: Control | None, contacts: Contacts | None,
            dt: float) -> None

state_in and state_out may alias for in-place stepping. Pass distinct SimState objects when the input buffer must be preserved. Collision is explicit: populate contacts with CollisionPipeline.collide before solver.step whenever the step should enforce contacts.

Solver Classes

Class	Description
SolverBase	Newton-aligned base contract.
SolverFeatherstone	Articulated-body Featherstone solver.
SolverIPC	IPC / libuipc solver (CUDA). May be None when IPC is not built.
SolverLBM	Lattice Boltzmann fluid backend.
SolverMPM	Material Point Method backend.
SolverPBF	Position Based Fluids solver.
SolverSPH	SPH fluid solver (CPU + optional CUDA).
SolverSemiImplicit	Free-body semi-implicit Euler + PGS.
SolverVBD	VBD / AVBD primal-dual solver (CPU SolverBase path).
SolverXPBD	XPBD maximal-coordinate constraint solver.

These entries are Newton-aligned SolverBase subclasses driven by the solver.step(state_in, state_out, control, contacts, dt) contract. SolverMPM and SolverLBM may report backend_info().is_scaffold when the corresponding backend is not implemented in the current build.

Configuration Objects

Class	Description
IPCConfig	IPC solver configuration.
PBFConfig	Position Based Fluids configuration.
SolverFeatherstoneSettings	Featherstone solver settings.
SolverSettings	Shared rigid solver settings (semi-implicit / XPBD shared knobs).
SPHConfig	SPH solver configuration.
VBDConfig	SolverVBD configuration.
XPBDSolverSettings	XPBD-specific solver settings.

Enumerations and Metadata

Symbol	Description
JointSupportMatrix	Per-solver joint capability table.
SolverBackendInfo	Backend descriptor (device, fixed-dt, etc.).
SolverBackendKind	Backend device classifier.
SolverNotifyFlags	Cache invalidation flags after Model mutation.
SolverStateOwnership	Whether a solver owns its own state.
SPHBackendKind	SPH explicit backend selector (CUDA when available).
VbdBackend	VBD backend selector (CPU / CUDA).

Legacy Backend Containers

In IPC-enabled builds, novaphy.IPCWorld remains a backend container exposed at the top level of novaphy (not under novaphy.solvers). It is not a Newton-aligned SolverBase subclass, is not advertised in novaphy.__all__, and emits a DeprecationWarning on construction.

Container	Target / replacement	Status
novaphy.IPCWorld	SolverIPC	Deprecated — prefer SolverIPC.