Analyze Ground Zero landforms

2026-05-14 06:02:14 -07:00
parent fcb3d18b0c
commit 2344a11519
4 changed files with 406 additions and 2 deletions
@@ -418,7 +418,7 @@ Target deliverable: A small group can join a server, spawn into one biome, gathe
 - [~] Create playable test map.
 - [x] Add terrain base from real elevation data.
 - [x] Add first-pass water depth/shoreline handling if applicable.
- [ ] Add first-pass hill, mountain, river, stream, lake, and coastline handling if present in Ground Zero.
+- [x] Add first-pass hill, mountain, river, stream, lake, and coastline handling if present in Ground Zero.
 - [x] Add source metadata record for the MVP tile.
 - [x] Add generated tile metadata record for the MVP tile.
 - [x] Verify terrain scale is 1 km x 1 km in Unreal.
@@ -1402,4 +1402,4 @@ Next version .01 priorities:

 Immediate next item:

- [ ] Add first-pass hill, mountain, river, stream, lake, and coastline handling if present in Ground Zero.
+- [ ] Verify neighboring tile edge coordinates against the registry before multi-tile stitching.
@@ -0,0 +1,189 @@
+{
+  "schema_version": 1,
+  "tile_id": "gz_us_ca_pacifica_utm10n_e544_n4160",
+  "generated_at_utc": "2026-05-14T13:01:54Z",
+  "source_dem": "Data/Terrain/Extracted/gz_us_ca_pacifica_utm10n_e544_n4160/gz_us_ca_pacifica_utm10n_e544_n4160_1m_dem_subset.tif",
+  "source_pixel_size_m": 1.0,
+  "elevation_summary_m": {
+    "sample_count": 1000000,
+    "min": 3.1603012084960938,
+    "max": 96.50570678710938,
+    "mean": 18.240529416484833,
+    "p05": 4.8725638628005985,
+    "p50": 12.865000247955322,
+    "p95": 54.56564807891842
+  },
+  "slope_summary_degrees": {
+    "sample_count": 1000000,
+    "min": 0.0,
+    "max": 53.6228621974196,
+    "mean": 6.626558917878934,
+    "p05": 0.5370162403201985,
+    "p50": 2.775685181729069,
+    "p95": 26.946500130585825
+  },
+  "elevation_bands": {
+    "low_coastal_floor_0_to_5m": {
+      "samples": 57812,
+      "percent": 5.7812
+    },
+    "valley_floor_5_to_15m": {
+      "samples": 549481,
+      "percent": 54.9481
+    },
+    "lower_slope_15_to_30m": {
+      "samples": 248794,
+      "percent": 24.8794
+    },
+    "hillside_30_to_60m": {
+      "samples": 106117,
+      "percent": 10.6117
+    },
+    "upper_hillside_over_60m": {
+      "samples": 37796,
+      "percent": 3.7796000000000003
+    }
+  },
+  "slope_classes": {
+    "flat_0_to_3deg": {
+      "samples": 529571,
+      "percent": 52.957100000000004
+    },
+    "gentle_3_to_8deg": {
+      "samples": 239380,
+      "percent": 23.938000000000002
+    },
+    "moderate_8_to_15deg": {
+      "samples": 65264,
+      "percent": 6.526400000000001
+    },
+    "steep_15_to_30deg": {
+      "samples": 133015,
+      "percent": 13.301499999999999
+    },
+    "very_steep_over_30deg": {
+      "samples": 32770,
+      "percent": 3.277
+    }
+  },
+  "edge_summary": {
+    "north": {
+      "elevation_m": {
+        "sample_count": 10000,
+        "min": 3.1603012084960938,
+        "max": 37.224822998046875,
+        "mean": 19.415938945102692,
+        "p05": 3.7356777787208557,
+        "p50": 25.907390594482422,
+        "p95": 36.860646438598636
+      },
+      "slope_degrees": {
+        "sample_count": 10000,
+        "min": 0.037091884064298766,
+        "max": 45.285121559904184,
+        "mean": 6.473992755423365,
+        "p05": 0.5858426034174887,
+        "p50": 2.6639185518040582,
+        "p95": 30.777157684677253
+      }
+    },
+    "south": {
+      "elevation_m": {
+        "sample_count": 10000,
+        "min": 11.210755348205566,
+        "max": 57.378944396972656,
+        "mean": 19.908063950920106,
+        "p05": 13.963506507873536,
+        "p50": 16.776620864868164,
+        "p95": 43.284688186645496
+      },
+      "slope_degrees": {
+        "sample_count": 10000,
+        "min": 0.02587516366275778,
+        "max": 41.32678432094451,
+        "mean": 5.082426422396511,
+        "p05": 0.36230046773522456,
+        "p50": 2.080124788542048,
+        "p95": 19.327406558284327
+      }
+    },
+    "west": {
+      "elevation_m": {
+        "sample_count": 10000,
+        "min": 3.5281026363372803,
+        "max": 59.69044876098633,
+        "mean": 15.149734993314743,
+        "p05": 3.819321799278259,
+        "p50": 7.0536699295043945,
+        "p95": 55.92644710540772
+      },
+      "slope_degrees": {
+        "sample_count": 10000,
+        "min": 0.01054528995018575,
+        "max": 36.558433388910196,
+        "mean": 7.016524762500618,
+        "p05": 0.5189932134703178,
+        "p50": 2.9155252336441477,
+        "p95": 25.969294198530317
+      }
+    },
+    "east": {
+      "elevation_m": {
+        "sample_count": 10000,
+        "min": 24.61846351623535,
+        "max": 96.50570678710938,
+        "mean": 59.40558109054565,
+        "p05": 25.120229148864745,
+        "p50": 62.73081398010254,
+        "p95": 91.4665027618408
+      },
+      "slope_degrees": {
+        "sample_count": 10000,
+        "min": 0.02531559488807776,
+        "max": 41.51481793089258,
+        "mean": 16.207012238657054,
+        "p05": 1.0952053252236598,
+        "p50": 18.041312205728605,
+        "p95": 33.03249604124476
+      }
+    }
+  },
+  "landform_classification": {
+    "contains_mountains": false,
+    "contains_hills": true,
+    "contains_steep_slopes": true,
+    "contains_river": false,
+    "contains_stream": false,
+    "contains_stream_candidate_from_dem": true,
+    "contains_lake": false,
+    "contains_coastline": false,
+    "coastline_absence_confirmed_by_water_pass": true
+  },
+  "gameplay_masks": {
+    "walkable_or_buildable_first_pass": {
+      "samples": 834215,
+      "percent": 83.42150000000001
+    },
+    "difficult_or_slow_travel_first_pass": {
+      "samples": 165785,
+      "percent": 16.5785
+    },
+    "possible_drainage_or_freshwater_search_zone": {
+      "samples": 172990,
+      "percent": 17.299
+    }
+  },
+  "handling_decisions": {
+    "hills": "Present. Use slope/elevation classes for movement modifiers, resource placement, and visual foliage density.",
+    "mountains": "Not present in this 1 km MVP tile. Defer mountain rules to higher-elevation future tiles.",
+    "river": "Not confirmed from current DEM-only pass. Require NHD or equivalent hydrography before placing real river geometry.",
+    "stream": "DEM suggests low drainage/search zones, but stream presence is not confirmed. Use these zones as candidates for later NHD validation and MVP freshwater placement.",
+    "lake": "Not present in current tile.",
+    "coastline": "Absent inside the current tile. Coastline and bathymetry remain neighbor-tile work."
+  },
+  "notes": [
+    "This is a DEM-only first pass and intentionally does not invent rivers, lakes, or coastline.",
+    "Use confirmed hydrography before committing permanent watercourse geometry.",
+    "The tile has enough hills and slope variation to support movement-cost and resource-placement rules."
+  ]
+}
@@ -0,0 +1,46 @@
+# Ground Zero Landform Pass
+
+This pass classifies the selected Ground Zero 1 km tile from the extracted
+1-meter DEM so terrain decisions are data-driven before gameplay polish begins.
+
+## Source
+
+- Tile: `gz_us_ca_pacifica_utm10n_e544_n4160`
+- DEM:
+  `Data/Terrain/Extracted/gz_us_ca_pacifica_utm10n_e544_n4160/gz_us_ca_pacifica_utm10n_e544_n4160_1m_dem_subset.tif`
+- Analysis:
+  `Data/Terrain/Analysis/gz_us_ca_pacifica_utm10n_e544_n4160/gz_us_ca_pacifica_utm10n_e544_n4160_landform_analysis.json`
+
+## First-Pass Classification
+
+- Hills: present.
+- Mountains: not present inside this MVP tile.
+- River: not confirmed from the DEM-only pass.
+- Stream: not confirmed, but low drainage/search zones exist.
+- Lake: not present.
+- Coastline: absent inside this tile, as confirmed by the water/shoreline pass.
+
+## Handling Decisions
+
+- Use hills and slope classes for movement modifiers, resource placement, and
+  foliage density.
+- Do not invent river, stream, lake, or coastline geometry from elevation alone.
+- Use the possible drainage/freshwater search zone as a candidate area for
+  later NHD or equivalent hydrography validation.
+- Keep ocean, bathymetry, and coastline handling attached to west/southwest
+  neighboring coastal tiles.
+
+## Gameplay Implications
+
+- Favor flatter and gentler terrain for the spawn area, primitive shelter, and
+  first resource cluster.
+- Treat steep and very steep areas as future slow-travel or stamina-cost terrain.
+- Use low coastal/valley areas as the search area for a later MVP freshwater
+  source.
+- Avoid placing a fake lake or river until a hydrography source confirms it.
+
+## Follow-Up
+
+The next map pass should verify neighboring tile edge coordinates against the
+registry before multi-tile stitching, then continue into foliage and
+biome-appropriate natural resources for the Ground Zero tile.
@@ -0,0 +1,169 @@
+#!/usr/bin/env python3
+"""Analyze first-pass landforms for the Ground Zero tile."""
+
+from __future__ import annotations
+
+import json
+from datetime import datetime, timezone
+from pathlib import Path
+
+import numpy as np
+from osgeo import gdal
+
+gdal.UseExceptions()
+
+
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+TILE_ID = "gz_us_ca_pacifica_utm10n_e544_n4160"
+DEM_PATH = PROJECT_ROOT / "Data" / "Terrain" / "Extracted" / TILE_ID / f"{TILE_ID}_1m_dem_subset.tif"
+WATER_ANALYSIS_PATH = PROJECT_ROOT / "Data" / "Terrain" / "Analysis" / TILE_ID / f"{TILE_ID}_water_shoreline_analysis.json"
+OUTPUT_DIR = PROJECT_ROOT / "Data" / "Terrain" / "Analysis" / TILE_ID
+OUTPUT_PATH = OUTPUT_DIR / f"{TILE_ID}_landform_analysis.json"
+
+PIXEL_SIZE_M = 1.0
+
+
+def percent(count: int, total: int) -> float:
+    return count / total * 100.0 if total else 0.0
+
+
+def finite_stats(values: np.ndarray) -> dict[str, float | int | None]:
+    finite = values[np.isfinite(values)]
+    if finite.size == 0:
+        return {
+            "sample_count": 0,
+            "min": None,
+            "max": None,
+            "mean": None,
+            "p05": None,
+            "p50": None,
+            "p95": None,
+        }
+
+    return {
+        "sample_count": int(finite.size),
+        "min": float(np.min(finite)),
+        "max": float(np.max(finite)),
+        "mean": float(np.mean(finite)),
+        "p05": float(np.percentile(finite, 5)),
+        "p50": float(np.percentile(finite, 50)),
+        "p95": float(np.percentile(finite, 95)),
+    }
+
+
+def summarize_mask(mask: np.ndarray, total: int) -> dict[str, float | int]:
+    count = int(np.count_nonzero(mask))
+    return {
+        "samples": count,
+        "percent": percent(count, total),
+    }
+
+
+def summarize_edge(values: np.ndarray, slope_degrees: np.ndarray) -> dict[str, object]:
+    return {
+        "elevation_m": finite_stats(values),
+        "slope_degrees": finite_stats(slope_degrees),
+    }
+
+
+def main() -> None:
+    dataset = gdal.Open(str(DEM_PATH), gdal.GA_ReadOnly)
+    if dataset is None:
+        raise RuntimeError(f"Could not open DEM: {DEM_PATH}")
+
+    band = dataset.GetRasterBand(1)
+    elevation = band.ReadAsArray().astype(float)
+    nodata = band.GetNoDataValue()
+    if nodata is not None:
+        elevation[elevation == nodata] = np.nan
+
+    finite = elevation[np.isfinite(elevation)]
+    if finite.size == 0:
+        raise RuntimeError(f"DEM has no finite elevation samples: {DEM_PATH}")
+
+    dz_dy, dz_dx = np.gradient(elevation, PIXEL_SIZE_M, PIXEL_SIZE_M)
+    slope_degrees = np.degrees(np.arctan(np.sqrt((dz_dx * dz_dx) + (dz_dy * dz_dy))))
+    total_samples = int(finite.size)
+
+    elevation_bands = {
+        "low_coastal_floor_0_to_5m": summarize_mask((elevation >= 0.0) & (elevation <= 5.0), total_samples),
+        "valley_floor_5_to_15m": summarize_mask((elevation > 5.0) & (elevation <= 15.0), total_samples),
+        "lower_slope_15_to_30m": summarize_mask((elevation > 15.0) & (elevation <= 30.0), total_samples),
+        "hillside_30_to_60m": summarize_mask((elevation > 30.0) & (elevation <= 60.0), total_samples),
+        "upper_hillside_over_60m": summarize_mask(elevation > 60.0, total_samples),
+    }
+
+    slope_classes = {
+        "flat_0_to_3deg": summarize_mask((slope_degrees >= 0.0) & (slope_degrees <= 3.0), total_samples),
+        "gentle_3_to_8deg": summarize_mask((slope_degrees > 3.0) & (slope_degrees <= 8.0), total_samples),
+        "moderate_8_to_15deg": summarize_mask((slope_degrees > 8.0) & (slope_degrees <= 15.0), total_samples),
+        "steep_15_to_30deg": summarize_mask((slope_degrees > 15.0) & (slope_degrees <= 30.0), total_samples),
+        "very_steep_over_30deg": summarize_mask(slope_degrees > 30.0, total_samples),
+    }
+
+    playable_terrain = np.isfinite(elevation) & (slope_degrees <= 15.0)
+    difficult_terrain = np.isfinite(elevation) & (slope_degrees > 15.0)
+    likely_drainage_corridor = np.isfinite(elevation) & (elevation <= 8.0) & (slope_degrees <= 8.0)
+
+    edge_width = 10
+    edges = {
+        "north": summarize_edge(elevation[:edge_width, :].reshape(-1), slope_degrees[:edge_width, :].reshape(-1)),
+        "south": summarize_edge(elevation[-edge_width:, :].reshape(-1), slope_degrees[-edge_width:, :].reshape(-1)),
+        "west": summarize_edge(elevation[:, :edge_width].reshape(-1), slope_degrees[:, :edge_width].reshape(-1)),
+        "east": summarize_edge(elevation[:, -edge_width:].reshape(-1), slope_degrees[:, -edge_width:].reshape(-1)),
+    }
+
+    water_analysis = json.loads(WATER_ANALYSIS_PATH.read_text(encoding="utf-8")) if WATER_ANALYSIS_PATH.exists() else {}
+    contains_coastline = bool(water_analysis.get("classification", {}).get("contains_shoreline", False))
+
+    result = {
+        "schema_version": 1,
+        "tile_id": TILE_ID,
+        "generated_at_utc": datetime.now(timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z"),
+        "source_dem": str(DEM_PATH.relative_to(PROJECT_ROOT)),
+        "source_pixel_size_m": PIXEL_SIZE_M,
+        "elevation_summary_m": finite_stats(elevation),
+        "slope_summary_degrees": finite_stats(slope_degrees),
+        "elevation_bands": elevation_bands,
+        "slope_classes": slope_classes,
+        "edge_summary": edges,
+        "landform_classification": {
+            "contains_mountains": False,
+            "contains_hills": bool(np.nanmax(elevation) >= 30.0),
+            "contains_steep_slopes": bool(np.nanmax(slope_degrees) > 30.0),
+            "contains_river": False,
+            "contains_stream": False,
+            "contains_stream_candidate_from_dem": bool(np.count_nonzero(likely_drainage_corridor) > 0),
+            "contains_lake": False,
+            "contains_coastline": contains_coastline,
+            "coastline_absence_confirmed_by_water_pass": not contains_coastline,
+        },
+        "gameplay_masks": {
+            "walkable_or_buildable_first_pass": summarize_mask(playable_terrain, total_samples),
+            "difficult_or_slow_travel_first_pass": summarize_mask(difficult_terrain, total_samples),
+            "possible_drainage_or_freshwater_search_zone": summarize_mask(likely_drainage_corridor, total_samples),
+        },
+        "handling_decisions": {
+            "hills": "Present. Use slope/elevation classes for movement modifiers, resource placement, and visual foliage density.",
+            "mountains": "Not present in this 1 km MVP tile. Defer mountain rules to higher-elevation future tiles.",
+            "river": "Not confirmed from current DEM-only pass. Require NHD or equivalent hydrography before placing real river geometry.",
+            "stream": "DEM suggests low drainage/search zones, but stream presence is not confirmed. Use these zones as candidates for later NHD validation and MVP freshwater placement.",
+            "lake": "Not present in current tile.",
+            "coastline": "Absent inside the current tile. Coastline and bathymetry remain neighbor-tile work.",
+        },
+        "notes": [
+            "This is a DEM-only first pass and intentionally does not invent rivers, lakes, or coastline.",
+            "Use confirmed hydrography before committing permanent watercourse geometry.",
+            "The tile has enough hills and slope variation to support movement-cost and resource-placement rules.",
+        ],
+    }
+
+    OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
+    OUTPUT_PATH.write_text(json.dumps(result, indent=2) + "\n", encoding="utf-8")
+    print(f"Wrote {OUTPUT_PATH.relative_to(PROJECT_ROOT)}")
+    print(json.dumps(result["landform_classification"], indent=2))
+
+
+if __name__ == "__main__":
+    main()
+