{
  "project": "Floating Terraced Garden / 漂浮台地花园",
  "version": "concept-v1",
  "purpose": "Three.js exploratory blockout; all dimensions are design assumptions, not measurements from AI artwork",
  "units": "meters",
  "coordinates": {"x": "right", "y": "up", "z": "toward viewer/front", "origin": "center of island in plan", "scene_extent_xz": [30, 30]},
  "palette": {"parchment": "#D9CDB9", "limestone": "#B8A489", "antique_gold": "#B38D50", "charcoal": "#272524", "water": "#7D999F", "root_red": "#924B42", "foliage_dark": "#565C51"},
  "terrain_levels_m": {"front": 1.0, "middle": 2.8, "upper": 5.1},
  "objects": [
    {"id":"T01","name":"Floating base terrain","type":"irregular extruded rock mesh","center_xyz":[0,-3,0],"size_xyz":[25,12,25],"geometry":"organic irregular perimeter; tapered hanging rock underside down to y=-9","notes":"Main structural landmass; no flat visible bottom"},
    {"id":"T02","name":"Front terrace","type":"polygon terrace","center_xyz":[0,1,5],"size_xyz":[20,1.2,11],"geometry":"irregular travertine ledge and walking surfaces","notes":"Main visitor level, y≈1.0"},
    {"id":"T03","name":"Middle terrace","type":"polygon terrace","center_xyz":[0,2.8,-1.5],"size_xyz":[17,1.1,10],"geometry":"stepped natural cliff, retaining edge","notes":"Connect front to upper by stone stair"},
    {"id":"T04","name":"Upper sacred grove terrace","type":"polygon terrace","center_xyz":[-0.5,5.1,-7],"size_xyz":[12,1.0,8],"geometry":"rough plateau with tree island","notes":"Highest planting platform and water head"},
    {"id":"A01","name":"Monumental arch","type":"extruded arch geometry","center_xyz":[0,12,-11],"size_xyz":[13,14,1.8],"geometry":"open semicircular arch with weathered stone, pale blue and gold patches","notes":"Foot of arch approx y=5; stands behind upper terrace; NOT a building"},
    {"id":"W01","name":"Upper spring","type":"shallow water pool","center_xyz":[-1,5.2,-7],"size_xyz":[4,0.2,3],"geometry":"irregular calm spring around roots","notes":"Headwater starts here"},
    {"id":"W02","name":"Middle stream and stepped cascades","type":"connected ribbon water geometry","center_xyz":[-1,3.4,-1],"size_xyz":[5,3.4,11],"geometry":"single downhill sequence; narrow flow, rock steps, shallow basins","notes":"Continuous from W01 to W03; verify physical downhill direction"},
    {"id":"W03","name":"Lower circular reflecting pond","type":"irregular rounded pond","center_xyz":[1.8,1.15,3.2],"size_xyz":[8.5,0.25,7],"geometry":"broad shallow basin with small planted island","notes":"Receives W02; rim surrounded by walking path"},
    {"id":"W04","name":"Front-right outflow waterfall","type":"waterfall ribbon","center_xyz":[5.5,-1.7,6],"size_xyz":[1.6,6.0,0.3],"geometry":"visible water spilling over pond's downhill edge","notes":"Outflow of W03 drops off floating island, not into a higher basin"},
    {"id":"P01","name":"Main curving promenade","type":"walkway mesh with stone pavers","center_xyz":[0,1.3,5],"size_xyz":[19,0.2,12],"geometry":"1.8m minimum usable width; winds around W03 and branches to stairs","notes":"Connected walkable path, avoid bridge to nowhere"},
    {"id":"P02","name":"Stone steps and small bridges","type":"steps and low bridges","center_xyz":[-4,2.5,0],"size_xyz":[5,4,9],"geometry":"landings connect levels 1.0 → 2.8 → 5.1","notes":"No blocked entrances; safe clearances for walkthrough"},
    {"id":"V01","name":"Ancient trees and planting","type":"stylized trees and underplanting","center_xyz":[0,5,-5],"size_xyz":[20,9,17],"geometry":"one focal gnarled red-canopy tree in upper grove, 5-7 smaller red and dark trees, shrubs","notes":"Individual tree transforms to be authored later"},
    {"id":"R01","name":"Hanging roots","type":"curved tubes and flat cutout accents","center_xyz":[-3,-5,6],"size_xyz":[16,10,14],"geometry":"terracotta-red roots dangle from island margins, especially front-left","notes":"Avoid crossing walking surfaces"},
    {"id":"D01","name":"Weathered pillars and small arches","type":"instanced stone/charcoal meshes","center_xyz":[0,1,-2],"size_xyz":[22,8,20],"geometry":"sparse slender columns and shallow under-terrace arcades","notes":"Secondary elements, landscape remains dominant"},
    {"id":"F01","name":"Fog and abstract backdrop","type":"environment","center_xyz":[0,0,-20],"size_xyz":[100,80,100],"geometry":"dark-to-parchment gradient mist; optional flat cartographic motifs","notes":"Graphic overlays are nonphysical; hide for strict geometry view"}
  ],
  "cameras": [
    {"id":"camera_hero","mode":"perspective","position_xyz":[28,22,32],"target_xyz":[0,3,-2],"fov_degrees":38,"notes":"Elevated three-quarter overview"},
    {"id":"camera_eye","mode":"perspective","position_xyz":[-4.5,2.65,8.0],"target_xyz":[0,4,-8],"fov_degrees":60,"notes":"Visitor standing on front-left promenade: 1.65m above terrace y=1"},
    {"id":"camera_front","mode":"orthographic","position_xyz":[0,8,35],"target_xyz":[0,5,0],"notes":"Poster-like front elevation"},
    {"id":"camera_top","mode":"orthographic","position_xyz":[0,40,0],"target_xyz":[0,0,0],"notes":"True plan view with up vector adjusted"}
  ],
  "water_flow_order": ["W01", "W02", "W03", "W04"],
  "implementation_notes": ["First produce a navigable graybox with Three.js, OrbitControls and FPS camera toggle", "Preserve continuous paths and physically downhill water flow", "Use simple geometry before PBR textures and atmospheric overlays", "Reference concept sheet is inspirational, not geometrically authoritative"]
}