Three levels and ramp hexagrams — the edge rule, the height-field mesh, the mirrors and the editor

done priority 1 estimate M

ground-look-and-levels/002 · created 2026-08-18 · updated 2026-08-18

What to do

Decisions 3–6 of the workshop note (land-of-lor/docs/design/2026-08-18-ground-look-and-levels-workshop.md), with its provisional hexagrams (kw 27 high, kw 41 low, kw 42 and 61 ramps) until the meanings pass (005) replaces them.

Data: level (−1/0/+1, default 0) and ramp: true on hexagrams in elements.js; ground_types.gd / groundTypes.ts read them.
grid.gd: at apply_ground/set_ground precompute per cell its level and, for ramps, the derived axis and direction (recomputed for the neighbours of a changed cell too); expose edge_level(x, y, dir) and is_ramp(x, y). Hot loops stay one array read.
movement.gd: the edge rule — the step A→B needs B walkable and the two surfaces meeting at the shared edge; diagonals need all four cells at one level and none a ramp. Client prediction gets it for free (it calls the same function). flow_field.gd: the same rule in its neighbour loop. New Result.LEVEL_BLOCKED with its reason string.
ground_mesh.gd: the height field — level × BLOCK − sink, ramps a plane between their two end levels — under the “highest touching cell” vertex rule; standing_height = the surface at the cell centre (a ramp’s centre is halfway); mountains and portals sit on their cell’s surface. world_units.gd: LEVEL_HEIGHT (a full cell to start; Kris tunes it over time).
ground.gdshader: cliff faces (steep, tall steps) shaded as an earth wall with a lip line along the top edge; a bank (a sink) keeps its lighter rim.
One shared game/shell/ground_rules.mjs (ES module, browser and node): canStep, reachableFrom with the corner rule and the level rule; director/src/groundContent.ts and tools/world-editor/area-editor.js use it (the editor is already served from shell/ by server.mjs). The editor: palette shows level/ramp on a hexagram’s chip text, Random mix and the director’s sprinkle presets never pick a levelled or ramp hexagram, loose ends flag a ramp with no level change beside it and a ramp with two candidate axes; the loader refuses the same things it always did, now with the level rule in its reachability.
_shots.gd’s built-in showcase gains a plateau with a ramp and a pit with a ramp; take the chase-camera shot with a body at the foot of a cliff on the camera side — the occlusion check that decides whether LEVEL_HEIGHT stays a full cell.
Tests: test_runner.gd (rule cases: same level, ramp ends, ramp flanks, diagonals, dead ramp, derived axis; mesh heights on a plateau and a ramp) and director tests (groundContent reachability with a cliff and a ramp).

Definition of done

All of the above green; the showcase shots in docs/handoff/ground-look-and-levels/; a docs/handoff/ground-look-and-levels.md note with what was decided in the build (block height after the occlusion check, ramp edge cases). No protocol or schema change. Committed and pushed.

Where the work lands

land-of-lor/game/world/, game/shell/, game/director/src/, tools/world-editor/, docs/handoff/.

What was done (2026-08-18, laptop workshop session)

Built and shipped the same day. Kris’s assignments (not the provisional four): the Deep Water family is the deep level (−1, wadeable), Wind over Lake the ramp down; Mountain over Stone the high level, Wind over Stone the ramp up; the Grass family reserved for variety. One shared game/shell/ground_rules.mjs (levels, derived ramps, the whole step rule) for the director’s loader validation and the area editor; grid.gd precomputes levels/ramp directions; movement.gd (LEVEL_BLOCKED) and flow_field.gd ask it; the mesh is a height field on the same lattice; the shader keeps a plateau’s blend to its level and paints faces; the editor says every chip’s meaning, mixes only variety, flags a level change with no ramp and odd ramps; the showcase has a plateau + ramp, a pit + ramp, and the occlusion shot (LEVEL_HEIGHT stays a full cell: legs hidden, torso and head visible). test_runner 247/247, director 202/202. Handoff: land-of-lor/docs/handoff/ground-look-and-levels.md.

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