Distant foliage LOD terminates in a PBR material (geometry→material continuum)

Extension of the LOD-as-statistics synthesis #CYDXJ2 the terminal object of a continuous foliage LOD ladder is a PBR material, because PBR materials ARE renormalized geometry — the microfacet NDF is a histogram of sub-pixel normals, roughness is its variance, and the shadowing-masking term G is statistical self-occlusion. The geometry/material boundary is scale-relative (set by pixel footprint), so LOD = migrating structure across that boundary.

Corpus evidence: Bruneton–Neyret shader-maps are literally a “PBR forest material” — view/light-dependent terrain reflectance with view-light masking correlations, i.e. a G-term whose microfacets are trees #7R6ZNJ their pre-transition convergence #D4D5AP is geometry converging to its material. HZD grass already terminates as G-buffer material parameters: roughness/reflectance #3JHMBP translucency #MXZG4T

Caveats for a “PBR grass material”: cannot naively mip material parameters (filtering ≠ shading; lost normal variance must convert to roughness, cf. LEAN/LEADR appearance prefiltering). Far-field grass BRDF is anisotropic (vertical blades, clump-facing azimuth structure), translucent (needs BTDF), optically deep (better as thin anisotropic microflake volume, Neyret volumetric-texture lineage), with view-light correlated self-shadowing (hotspot effect).

Design implication (e.g. for moppe): per-blade instance parameters #66DTCB height, width, tilt, bend, clump facing, color) are the sufficient statistics of the far field — aggregate their moments per tile plus coverage #WZDZZW to DERIVE the distant material’s parameters from the same generative model, ensuring near/far expectations agree by construction. Slogan: a material is what a distribution of geometry looks like from far enough away.