Seeing beginner ray-tracing experiments evokes not-so-fond memories of my own first experiences with ray-tracing (and 3D rendering of any kind). Around 1987 I t

Seeing beginner ray-tracing experiments evokes not-so-fond memories of my own first experiences with ray-tracing (and 3D rendering of any kind). Around 1987 I tried a brand new ray tracing program called Sculpt 3D on my Commodore Amiga 1000 (7Mhz 68000 / 512K RAM). I'd been lured into buying the software (for $99 IIRC) when I saw a looping ray-traced animation called The Juggler at a local user group meeting (http://www.etwright.org/cghist/juggler.html http://www.etwright.org/cghist/juggler.html). This despite the salesman at the computer shop warning me, "Yeah, so... 3D is really hard and slow." With no knowledge, experience or clue I enthusiastically raced home to boot up the diskette and dive into what I naively imagined would be a journey toward making my own Tron-like images. I cracked open the manual and pretty quickly figured out how to create a new scene, add a sphere to it and apply what promised to be a shiny chrome texture to the sphere. Of course without rendering it all I could see on the screen was a wireframe. So I anxiously clicked the magic Render button and the screen went black. I knew the results wouldn't be instant so I went and made a sandwich for lunch. Upon returning to check in on my masterpiece, the screen was still completely black. I went and watched a TV show. Still nothing on the screen yet. I went out and did some errands. Still nothing but black. After dinner, I checked back and finally saw the "Render Complete!" message. But the screen was still completely black. I went to bed demoralized. The next day I stopped back by the computer store to seek some advice (or, at least some sympathy). Being a Sunday there were several users hanging around talking and playing games. The assembled brain trust was stumped until one guy asked, "Did you add a light to the scene?" Doh! Suffice to say, I produced no images worth saving (or remembering) in those early days :-). The one positive from my newbie experience was that years later I was involved in software product management, marketing and design, including a few 90s 3D renderers. I ensured that every one of them either included a default light in a new blank scene or warned the user if they clicked Render with no lights in the scene.