ReadonlydataReadonlywidthReadonlyheightReadonlyoriginReadonlyoriginReadonlyextentReadonlyextentWhether the world XZ point lies inside the mapped rect.
Bilinear normalized height at a world XZ point, or null outside the
rect (callers substitute their floor height — mirroring the page-gen
shader's floor_height behavior outside the heightmap rect).
A normalized [0, 1] height field over a world-space rect, sampled bilinearly. Row-major
width × heightsamples; texel (0, 0) sits at (originX,originZ) and texel (width-1, height-1) at (originX + extentX,originZ + extentZ) — the same mapping the page-gen shader uses when it samples the heightmap texture with a clamping sampler.