Here is the result of my own implementation of the book Ray Tracing in One Weekend.
The main difference between my implementation and the one presented in the book is that I use triangular meshes instead of just perfect spheres. As a consequence, I can show much more complicated objects, but the drawback is that it takes a very long time to render because I didn’t implement any optimized data structure to intersect rays with triangles. This image is full HD with 1024 samples per pixels and rendering it took half a day on a computer equipped with a Xeon Phi 7210 with 64 cores at 1,30 GHz.
More information
Link to the GitHub repository: mgaillard/Renderer
Link to the online book: Ray Tracing in One Weekend