[fizixer]

> Is there a reason to make this distinction here?

The original method, by Whitted, that looked much better than any previous methods, and yet looks horrible by today's standards, is ray tracing. It had no global illumination.

The method based on solving, explicitly or implicitly, the rendering equation by James Kajiya, and one that has built-in global illumination, is path tracing.

The distinction is not important for buzzword hijacking hacks, marketing gimmickers, and snake oil salesmen.

[dahart]

I could broadly agree with your first two sentences, even though it's not actually true that ray tracing didn't have global illumination before the Rendering Equation came along. Recursive ray tracing, diffuse inter-reflections, distribution ray tracing, all these things existed before the term path tracing came along. Path tracing is more of a unifying formalism than a distinction between global illumination and direct lighting.

I'm completely stumped by your last sentence though, I have no idea where your anger is coming from. But it fails to explain why you want to make the distinction in this thread, since, as I already pointed out "Ray Tracing in one Weekend" is doing both (for example chapters 1-7 are the mechanics of ray tracing, no path tracing concepts are used until chapter 8). Are you referring indirectly to any specific products that have marketing you don't like? Your story can't explain people who use the term "ray tracing" since they're being honest about not necessarily doing path tracing. So are you talking about someone who uses the term "path tracing" when they're not doing global illumination?

[tylermw]

What snake oil is being sold here with a free book? Who exactly is a hack? Sure, there's some technical differences between the two terms, but outside of the research community they are used interchangeably.

[fizixer]

Well. Looks like the hacks, gimmickers, and salesmen have succeeded wonderfully.