A minimal ray tracing engine written from scratch in JS. No graphics APIs or libraries are used, only a single HTML5 canvas call to draw the generated bitmap image.
Various effects are supported, including recursive optical reflections and refractions, and Phong shading. Basic multi-threading is implemented using the Web Workers API.
The raytracer can also produce CPU performance benchmarks.
The source is on GitHub.
You can also use the raytracer to run a CPU and JavaScript performance benchmark.
This will run multiple 1080p renders, with both single and multicore workloads. An overall score will be calculated based on performance, higher is better.
Compare your results to the reference scores from the various devices I've tested.