Shadertoy

Quilez’s article is the most practical bridge between the formal sphere-tracing literature and the way the technique is actually used in shader culture. Rather than stopping at the generic march-until-hit loop, it shows ray-marched SDFs as a complete creative workflow: scene construction in code, smooth blends, repetition, deformation, shading, shadows, and iteration toward final images. That is why it remains so influential for practitioners: it teaches the method as a living medium for procedural scene-building, not just as an intersection routine.

Another reason it is distinctive is historical and aesthetic. The article places modern SDF ray marching in a lineage that includes older implicit-surface work while also documenting the demoscene and Shadertoy style that made the technique widely legible to graphics programmers. The result is a reference that is less formal than Hart but far richer in modeling intuition, especially if you want to understand why repetition, domain distortion, and compact signed-distance code became central patterns in realtime procedural rendering.