yuki

Ray cast renderer mostly based on Physically Based Rendering 3rd edition (pbrt-v3) with some additions from pbrt-v4.

Running

The project can be run most easily with

cd yuki && cargo run --release

Mouse controls

• MMB drag / LMB drag + Alt - Trackball drag
• Scroll up/down - Dolly forward/back
• MMB drag + Shift / LMB drag + Shift + Alt - Plane drag
• LMB + Ctrl - Fire debug ray

Goals

• Explore offline rendering techniques
• Try out how Rust helps/complicates a moderately complex system
  • Including vectorization, at some point, hopefully...
• Prioritize interactivity
  • Shorter iteration times for scene, parameter tweaks mean more exploration and validation

Features

UI

• Settings from yaml
  • Ui button that generates a full dump of current settings
• Uniformly scaling film view
• Tone mapping
  • Filmic ACES tonemap (Stephen Hill's fit) with exposure
  • Heatmap
    • Single channel or luminance
    • Dynamic fitting of min,max
• ~Non-blocking rendering
  • Relevant ui changes cause a new render task
  • Full tile and accumulating modes
  • 1/16th res (res/4) "interactive" render when camera is being moved for responsiveness with heavy scenes
• EXR export for the raw values or tone mapped output
  • HDRView is snappy for inspection and diffs
• Basic mouse control for camera
  • Trackball, planar track, dolly
  • Adapted from Max Liani
• Rasterized debug rays
• Headless rendering to .exr

Renderer

• Tile-based rendering
  • Unwinding spiral pattern
    • Camera controls usable with longer frame times than if rendered row-by-row
  • Active work tiles can be marked
    • Not separately cleared when film clear is disabled to minimize lag
• BVH
  • Splits
    • Surface area heuristic
    • Middle
    • Equal counts
• Integrator abstraction
  • Whitted
    • Direct diffuse lighting
    • Shadows
    • Mirror specular reflections and transmission
  • Path
    • Russian roulette based on contribution after 3 bounces
  • Normals debug
  • BVH intersections debug
• Samplers
  • Use the pbrt-v4 seeking interface instead of pbrt-v3's pre-computed pixel samples
    • Much nicer with the accumulating mode, should now match non-accumulating exactly
  • Uniform
  • Stratified
• Light types
  • Point
  • Spot
  • Rectangular
• Material types (pbrt's Material/BSDF/BxDF abstraction)
  • Matte
    • Lambertian for rough, Oren-Nayar otherwise
  • Glass
    • Perfect only
  • Metal
    • Torrance-Sparrow with Trowbridge-Reitz/GGX distribution and Fresnel equations for conductors
  • Glossy
    • Torrance-Sparrow with Trowbridge-Reitz/GGX distribution and Schlick's Fresnel approximation
    • Approximates Blender's Glossy BSDF
• Textures
  • Albedo only for now
  • Point sampling
• Geometric and shading normals

Scene formats (partially) supported

• PLY
• Mitsuba 2.0
• pbrt-v3
  • A simple Blender exporter is also included
  • glossy material type
    • Takes in spectrum/rgb Rs and float roughness, which match Blender's Glossy BSDF parameters

yuki_derive

The math module is an excercise in new stuff, most notably proc_macros inspired by derive_more. The implementation itself is quite specific to how the types are structured and supports non-conventional stuff like "deriving" math ops with scalar values or other "vectors" of matching dimensions.

The macro spaghetti is overkill and likely more code than implementing the same stuff directly, especially if done through standard macros. But hey, it's cool I don't have to list component names for the impl macro :P

License

While the main repo is licensed under MIT, parts of it are derived from projects licensed under different, compatible terms. See LICENSES for details.