All four road tiers now carve into the 3D world. Rugged and Trail were
generated, exported and parsed all along, but nothing ever consumed them —
which is why county roads visible on the 2D map did not exist in 3D.
Tier identity is now carried into the carve via a RoadSegment struct, so each
tier gets its own width, shoulder and grade-smoothing from one tunable block in
Constants: highways widest and holding a grade, trails narrow and hugging the
land. Rugged and Trail surface as dirt rather than asphalt.
Because tiers now have different reach, nearest-by-distance was no longer a
sound way to pick the governing road — a nearby footpath could shadow a highway
whose shoulder still covered the column. The carve now considers only roads
whose shoulder actually reaches, and takes the closest of those.
The per-chunk cull pad is derived from the widest shoulder plus a margin, so
widening a road cannot silently truncate it at chunk edges.
Untouched: density field, Marching Cubes interpolation/welding, chunk dims,
the .dat contract, the 2D A* generation, and mesher normals.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Road elevation is now sampled at the point on the road segment nearest the
column being carved, instead of at the segment's midpoint. The old behaviour
gave every column near a segment that segment's single midpoint height, so each
stretch of road was one flat plank and consecutive planks stepped like a
staircase wherever the road crossed a gradient.
Elevation now varies continuously along the segment, and because neighbouring
segments share an end point the height matches exactly at the joins. A new
ROAD_GRADE_SMOOTHING constant dials between holding a straight grade
(cut-and-fill) and hugging the land, per D-021.
Untouched: density field, Marching Cubes, chunk dimensions, the .dat contract,
and the 2D A* road network itself. Only how existing paths are carved into 3D.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Vertex colour is now chosen from the true, unrounded surface height and faded
between adjacent materials across a tunable band, instead of switching at one
rounded integer depth. This removes the horizontal contour banding.
Colour path only: density field, Marching Cubes interpolation/welding, chunk
dimensions, the .dat contract and all road logic are untouched. BlockID
classification is unchanged and still drives non-visual use.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
