Struct NematicEngine 

pub struct NematicEngine { /* private fields */ }

Active nematohydrodynamics engine on a Riemannian 2-manifold.

Implementations

impl NematicEngine

pub fn new<M: Manifold>( mesh: Mesh<M, 3, 2>, manifold: M, params: NematicParams, gaussian_curvature: Vec<f64>, ) -> Result<Self, String>

Construct the engine from a mesh, manifold, and dimensionless parameters.

Precomputes all DEC operators, connection Laplacian, Stokes solver, and semi-Lagrangian data structures. The timestep is auto-computed from the diffusive CFL bound based on the mean edge length.

pub fn dt(&self) -> f64

The auto-computed timestep.

pub fn set_dt(&mut self, dt: f64)

Override the timestep (use with caution).

pub fn n_vertices(&self) -> usize

Number of vertices in the mesh.

pub fn params(&self) -> &NematicParams

The dimensionless parameters.

pub fn step(&self, q: &mut QFieldDec) -> VelocityFieldDec

Advance the nematic field by one timestep using operator splitting.

1. Stokes solve for velocity from active stress.
2. Semi-Lagrangian advection (backward trace + barycentric interp).
3. Diffusion + bulk LdG (explicit, connection Laplacian).

pub fn run( &self, q: &mut QFieldDec, n_steps: usize, snap_every: usize, callback: impl FnMut(usize, &QFieldDec, &VelocityFieldDec, &EngineStats), )

Run the engine for n_steps, calling the callback at each snapshot.