This is a great introduction to ray tracing and building a ray tracer in Go! I appreciate how you emphasize the importance of understanding the underlying concepts rather than just coding. The use of the PPM format for image output is a smart choice for simplicity, making it easy to visualize what's being rendered without getting bogged down in complex file formats.
The provided code snippet is clear and serves as a solid foundation for beginners. I’m especially interested in the exercise you suggested—creating a chessboard pattern is a fun way to get familiar with pixel manipulation and the idea of conditional rendering.
As you delve into defining the Vec3 and Ray structs, it would be helpful to explain how these structures relate to the math of ray tracing. Clarifying how vectors and rays are used in the rendering process will enhance the understanding of anyone following along. Looking forward to seeing how you expand this concept further!