Your description portrays raymarching as an optimization over raytracing and that's simply not the case at all. Raymarching enables rendering objects/scenes ra

Your description portrays raymarching as an optimization over raytracing and that's simply not the case at all. Raymarching enables rendering objects/scenes raytracing can't readily handle (like procedurally generated fractals), and tends to be costly because of how the ray must be "marched" towards the surfaces rather than directly computing intersections. The only form of raytracing I'm familiar with that employs anything resembling raymarching is the classical 80s-era KD-tree acceleration structure paper which stepped the ray at hyperplane boundaries, to confine the costly ray->object interesection tests to objects in the intersected axis-aligned bounding boxes.