Struct ConvexContactRollout 

pub struct ConvexContactRollout<'a> {
    pub model: &'a Model,
    pub ground_height: f64,
    pub material: ContactMaterial,
    pub config: ContactSolverConfig,
    pub q0: DVec,
    pub v0: DVec,
    pub steps: usize,
    pub ctrl: &'a dyn Fn(usize) -> DVec,
}

A differentiable rollout through the forward simulator’s contact path.

The forward dynamics are exactly phyz::Simulator::step_with_contacts: ground contact detection with margin, convex assembly, warm-started active-set Newton solve, semi-implicit Euler integration.

Fields

model: &'a Model

Topology, gravity, timestep, damping, geometry and nominal inertias.

ground_height: f64

World z of the ground plane (m).

material: ContactMaterial

Contact material for every body (the same single-material convention Simulator::step_with_contacts uses).

config: ContactSolverConfig

Solver configuration. Use ContactSolverConfig::simulation to differentiate the physics the simulator ships, or ContactSolverConfig::gradients for smoother sensitivities.

q0: DVec

Initial joint positions (Model layout, length nq).

v0: DVec

Initial joint velocities (length nv).

steps: usize

Number of steps.

ctrl: &'a dyn Fn(usize) -> DVec

Open-loop control at step t (length nv; must not read the state).