Repository Guidelines

Project Structure & Module Organization

raw_dgm1/: source DGM1 tiles (.tif + .tfw) named dgm1_<utm_zone>_<easting>_<northing>.tif.
raw_3dgeb_lod1/ and raw_3dgeb_lod2/: LoD1/LoD2 building geometries as .gml with sidecar .txt metadata.
raw_dop/: orthophoto download artifacts (scripts, certs, jp2, xml, j2w); treat as read-only inputs.
export_unity/: delivery assets; height_png16/ holds 16-bit heightmaps, tile_index.csv maps tile IDs to world bounds and global min/max.
work/: transient artifacts such as dgm.vrt and intermediate _tmp.tif files; safe to regenerate.
3dgeblod1/, 3dgeblod2/, dgm/: preserved ZIPs and object lists documenting raw downloads; keep for provenance.
export_heightmaps.py: main Python pipeline that mosaics the VRT, rescales to UInt16, and writes Unity-friendly tiles.

Create/refresh VRT (run in repo root):
gdalbuildvrt work/dgm.vrt raw_dgm1/*.tif
Export Unity-ready heightmaps and manifest:
python3 export_heightmaps.py
Inspect a tile for sanity (optional spot check):
gdalinfo export_unity/height_png16/dgm1_32_328_5511.png | head
Dependencies: GDAL with Python bindings (osgeo) available on PATH/PYTHONPATH.
If processing LoD GML or DOP imagery, keep scripts/data under the respective raw_* folders; avoid scattering inputs.

Python: 4-space indentation, snake_case identifiers, and module-level constants for tunables (e.g., TILE_SIZE_M, OUT_RES).
Keep tile IDs stable and lower_snake_case to align with file naming and manifest entries.
Prefer small, composable functions if extending the pipeline; keep GDAL options explicit.

No formal test suite yet; validate changes by re-running export_heightmaps.py on a small subset and diffing outputs.
For correctness, compare gdalinfo stats of regenerated PNGs against expectations and spot-check manifest bounds.
When altering scaling or bounds logic, document rationale in comments and update an example command in this guide if needed.

Use short, imperative commit messages (e.g., “add resampling flag”, “document export flow”); follow existing history style.
PRs should summarize scope, list commands executed (gdalbuildvrt, export_heightmaps.py), and call out data changes or new dependencies.
Avoid committing large raw datasets if not required; prefer documenting download steps or using .gitignore for temporary exports.
Include screenshots or brief notes when changes affect Unity import workflows or manifest formats.
Note the presence of archived downloads in 3dgeblod* and dgm/; do not delete them without replacing provenance elsewhere.