Subtract 0.01 from every terrain vertex Z in the modern terrain vertex
shader, matching retail's per-draw nudge applied inside
ACRender::landPolysDraw(arg2=2). Coplanar building floors now always win
the depth test against the rendered terrain, so the visual "ground at
the building floor" reads as the building's floor, not as Z-fighting.
Constant 0.01f bit-equals retail's float literal 0.00999999978 when
rounded to single precision.
Render-only — physics reads the un-nudged heightmap via
TerrainSurface.SampleZ / SampleZFromHeightmap. The same render-vs-
physics split is already established for EnvCell render lift
(+0.02m at GameWindow.cs around the cell-mesh draw).
Retail anchors:
docs/research/named-retail/acclient_2013_pseudo_c.txt:1120769
docs/research/named-retail/acclient_2013_pseudo_c.txt:702254
Cross-ref:
docs/research/2026-05-25-issue-100-terrain-cutout-handoff.md
docs/superpowers/plans/2026-05-25-issue-100-terrain-cutout.md
Followed by Task 2 (delete the hiddenTerrainCells / BuildingTerrainCells
plumbing). Visible result of this commit alone: building floors stop
Z-fighting, but the 24m x 24m transparent rectangles persist until the
plumbing is removed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Deletes:
- TerrainChunkRenderer.cs (454 lines, replaced by TerrainModernRenderer)
- TerrainRenderer.cs (247 lines, older sibling, no production users)
- terrain.vert / terrain.frag (replaced by terrain_modern.{vert,frag})
Removes the temporary Task 8 perf-benchmark toggle (ACDREAM_LEGACY_TERRAIN
env var, _useLegacyTerrain field, parallel _terrainLegacy renderer
instance, [TERRAIN-DIAG/modern|legacy] label suffix). The modern path
is now the only path. Mirror N.5's mandatory-modern amendment: missing
GL_ARB_bindless_texture throws NotSupportedException at startup
(already in place via the BindlessSupport.TryCreate gate).
Three load-bearing research comments preserved verbatim from terrain.vert
into terrain_modern.vert before deletion: the MIN_FACTOR = 0.0 N-dot-L
floor block (cross-ref Lambert brightness split), the aPacked3 bit
layout, the gl_VertexID corner-table 2026-04-21 ConstructPolygons fix.
Also retires the now-orphaned _shader field (legacy terrain pipeline
was its only user).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Vertex shader for the modern terrain dispatcher. Bit-identical math
to today's terrain.vert (Phase 3c per-cell mesh + Phase G AdjustPlanes
lighting). The only structural change is the version + bindless
extension preamble — sampler access stays a regular sampler2DArray
uniform; bindless-ness is invisible at the GLSL level.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
