Raytracing Show and Tell
We began our meeting in our new home: the Yellowstone meeting room of Future Learn. We were greeted by @tomstuart, two loaves of bread, a rather blunt bread knife, a selection of beverages and a strange waiting room with a towel in it.
@tuzz kicked things off by composing a Computation Club theme song on the spot:
After some obligatory faffing with HDMI cables and USB-C dongles, we began to review what the club had been up to both inside and outside of our recent meetings on raytracing, initially based on Matt Pharr, Wenzel Jakob and Greg Humphreys' "Physically Based Rendering: From Theory To Implementation".
In @leocassarani's absence, @tomstuart showed us the club's first attempt at a raytracer: Raymond and Tom's fork of it with a minimap. We recapped that this was based on our reading of the introduction from the book and featured a few fundamental concepts:
- The eye
- The film
- The camera
- Light sources
- Spheres
- The scene
We heard that the club had since gone on to mob a new raytracer called "raze" which formed the basis of all subsequent experiments including implementing reflections and materials with different reflective properties.
With that, @tuzz took to the screen and ran us through the various projects he had built along the way.
He began with a faithful translation of the book's pbrt program in Rust called ray-tracer. He explained how he had used this to improve his idiomatic Rust knowledge but also to try to remain close to the book's implementation. He highlighted his implementation of typed vectors of various sizes as something he was keen to explore in Rust.
However, having been dazzled by @leocassarani's more visual efforts, @tuzz then switched to implementing a ray tracer in Rust called "Starlight" which produced some mightily shiny scenes:
@tuzz explained that he implemented reflections based on his understanding of the book but that the book's treatment was extremely dense so his implementation involved some guesswork.
He then moved on to build another ray tracer based on the Entity component system pattern called "Moonlight" using the Rust ECS library Specs. We briefly touched on the RustConf 2018 keynote by Catherine West on this topic.
Still not done with raytracing, @tuzz then switched to building tooling around the book's pbrt program and wrote a Ruby gem called pbrt to write pbrt input files using a Ruby DSL.
Finally, @tuzz discussed his experimental Ruby framework "Vivid" which wraps pbrt and allows users to describe animated 3D scenes in Ruby and render them into videos, e.g. Triforce and sphere fly-by.
