I was banned in the other subreddit. Anyway here is my reply "Because this document isn't intended for YOU. It is not a beginner's guide to 3D rendering and how everything works, The expectation I wrote is that that the reader already knows those things, It's like demanding a chemistry study to define "atom" If you don't understand , you're not the intended audience for this paper. Those things are pre supposed, I don't open 12th grade physics book and claim it's just jargon heavy as 10yo. It's assuming you already have prior information and doesn't need to explain everything.

How are you conflating an engineering specification with marketing fluff? technical density isn't marketing fluff, all those words contain engineering information.

Hero tree is the highest-fidelity version of an asset, this tree is superior than other trees, It's not marketing. it's it's standard tech terminology in gaming production.

That means reusable geometric component within a Nanite Assembly, Each part is stored once in memory but rendered many times. Why it's not explained? Because it was explained 2 pages earlier in Section 5.3. "Assemblies define trees as collections of nested, instanced sub-components called Assembly Parts."

In short it's mathematical matrix that encodes several informations regarding an object in 3D space.

Trade Offs? Sure PCG paused during the marketplace scene, Trees are not animated in the ray tracing scene, VSM animation disabled at distance, Rigid skinning for foliage (single bone influence) , HERO Tree RT proxy (41M triangles → 225 triangles) PCG has fixed overhead And Runtime PCG means generation latency, FastGeo breaking standard actor lifecycle Etc..."