Crate lux_aurumque 

lux-aurumque — a minimal transient path tracer in Rust.

Standard renderers compute steady-state radiance (light bounced until equilibrium). This one refuses that simplification: every photon path carries its cumulative optical length, which determines its arrival time. Binning by arrival time produces a time-resolved movie of a Gaussian pulse propagating through a Cornell-box scene reskinned in aurum — gold, copper, amber.

Run the demo render

Clone the repo and run:

cargo run --release -p lux-aurumque
ffmpeg -framerate 30 -i frames/frame_%04d.png \
       -c:v libx264 -pix_fmt yuv420p -crf 18 lux-aurumque.mp4

Library use

The crate exposes the path-tracing primitives (transient, camera, material, sphere, etc.) plus a re-export of SpectralBudget — the Faber–Krahn bound that refuses parameter combinations whose total path-length horizon would exceed 3 · T_1 for the bounded scene.

use lux_aurumque::{SpectralBudget, transient::C};

// 0.95 m room → T_1 ≈ 6.34 ns; admit up to 3·T_1 ≈ 19.0 ns.
let budget = SpectralBudget::for_scene_diameter(0.95, C as f64);
assert!(budget.admits(15e-9));
assert!(!budget.admits(25e-9));

See NOTES_PROCESS.md in the repository for the process-philosophical framing — Whitehead’s ontology mapped onto the renderer’s data flow.

Modules

camera

Pinhole camera. Generates rays through pixels, with optional sub-pixel jitter.

hit

Hit records and the Hittable trait — the abstract interface every scene primitive must implement.

material

Materials: how a surface scatters or emits light.

ray

Ray primitive.

scene

A small demo scene: a Cornell-box-style room of large spheres approximating walls, plus a small sphere pulse-emitter near the ceiling and a diffuse sphere on the floor that the wavefront will sweep across.

sphere

Analytic sphere intersection.

transient

The transient core.

vec3

Vector aliases and small geometric utilities.

Structs

SpectralBudget

A ceiling on the diameter a bounded sequential domain may reach before its becoming exceeds the principal eigenvalue of the underlying Laplacian.

Enums

BudgetError

Failure modes of SpectralBudget. The Display impl is informative enough to surface directly at a user-facing prompt.