I started teaching graphics in university 15 years ago. Then it was relatively easy. Today it feels hard since the state of graphics programming is horrible, in my opinion, both on GPUs and CPUs.
I think this is why @Peter_shirley's Ray Tracing in One Weekend does a software raytracer, and has it save to a simple text format.
I recall someone saying they'd rather have a raw buffer of pixels than even html/css/js. At least they'd get exactly what they want.
