prakash 0.23.3

Optics and light simulation — ray optics, wave optics, spectral math, physically-based rendering
Documentation

Prakash

Prakash (Sanskrit: प्रकाश — light, illumination, to make visible) — optics and light simulation for AGNOS

Physics of light: ray optics, wave optics, spectral math, lens geometry, and physically-based rendering primitives. Built on hisab for math foundations.

Features

Feature Default Description
ray yes Geometric optics: Snell's law, Fresnel equations, reflection, refraction, TIR, Beer-Lambert
wave yes Wave optics: interference, diffraction (single/double slit, grating), polarization, thin film
spectral yes Wavelength ↔ RGB, blackbody radiation (Planck), Wien's law, color temperature, photon energy
lens yes Thin lens equation, magnification, lensmaker's equation, mirrors, depth of field
pbr no Physically-based rendering: Fresnel-Schlick, GGX/Beckmann NDF, Cook-Torrance BRDF, Lambert
ai no Daimon/hoosh integration (network deps)
logging no Structured logging via PRAKASH_LOG env var
full — Enables all features

Architecture

prakash (this crate)
  └── hisab (math: vectors, geometry, calculus, numerical methods)

Consumers:
  kiran       ──→ prakash (physically-based lighting, lens effects)
  aethersafta ──→ prakash (compositor light math, color temperature)
  rasa        ──→ prakash (image filter optics: lens blur, chromatic aberration)
  joshua      ──→ prakash (simulation: laser puzzles, optics experiments)

Quick Start

use prakash::ray::{Medium, snell, fresnel_normal, brewster_angle, beer_lambert};
use prakash::spectral::{wavelength_to_rgb, color_temperature_to_rgb, wien_peak};
use prakash::lens::{thin_lens_image_distance, magnification};
use prakash::wave::{malus_law, single_slit_intensity};

// Snell's law: light entering glass from air at 30°
let refracted = snell(Medium::AIR.n, Medium::GLASS.n, 0.5236).unwrap(); // 30° in radians

// How much light reflects off glass at normal incidence?
let reflectance = fresnel_normal(1.0, 1.52); // ~4%

// What color is 550nm light?
let green = wavelength_to_rgb(550.0).unwrap();

// What color is a 2700K warm bulb?
let warm = color_temperature_to_rgb(2700.0);

// Where does a 50mm lens focus an object at 2 meters?
let image_dist = thin_lens_image_distance(50.0, 2000.0).unwrap();
let mag = magnification(2000.0, image_dist);

// Malus's law: light through a polarizer at 45°
let transmitted = malus_law(1.0, std::f64::consts::FRAC_PI_4); // 50%

Modules

Module Functions Description
ray snell, fresnel_*, reflect_2d/3d, critical_angle, brewster_angle, beer_lambert 12 common materials with refractive indices
wave interference_intensity, single_slit_intensity, double_slit_intensity, grating_maxima, thin_film_reflectance, malus_law Polarization state (Jones vectors)
spectral wavelength_to_rgb, planck_radiance, wien_peak, color_temperature_to_rgb, photon_energy Physical constants (c, h, k)
lens thin_lens_image_distance, magnification, lensmaker_focal_length, depth_of_field, combined_focal_length Mirror equations, lens classification
pbr fresnel_schlick, distribution_ggx, geometry_smith, cook_torrance, lambert_diffuse, ior_to_f0 Full metallic-roughness PBR pipeline

Building

cargo build --all-features
cargo test --all-features

Roadmap

See docs/development/roadmap.md.

License

GPL-3.0 — see LICENSE.