Build a CityJSON Cadastral Boundary Validator
Examine land parcel boundaries and building footprints inside CityJSON models to verify setback distances. Detect encroachments across municipal property lines and produce zoning compliance reports.
What you are building
The core problem, expected build, and operating context for this challenge.
Examine land parcel boundaries and building footprints inside CityJSON models to verify setback distances. Detect encroachments across municipal property lines and produce zoning compliance reports.
Municipal Land Records Examiner
Extract 2D building footprints and LandUse parcel geometries from CityJSON dataset.
Calculate minimum Euclidean distance between exterior building vertices and parcel limits.
Compare computed distances against mandatory front, rear, and side setback regulations.
Compile infraction summary highlighting encroaching vertices for planning authority.
Map viewer displaying parcel polygons, building bounds, setback violation buffers, and report log.
Synthetic CityJSON parcels generated from standard CityJSON v2.0 coordinate and LandUse schemas. Starter examples below are synthetic. They are not downloaded records.
CityJSON Extracts LandUse and Building CityObjects along with coordinate vertices and transform scale factors as defined in CityJSON 2.0.
qdrant, shapely, fastapi. Qdrant stores spatial attribute embeddings and zoning regulations to rapidly match local setback rules. Local or cloud LLM with strong geometric validation and structured report drafting abilities.
Submit runnable source, pinned dependencies, setup commands, a working interface, example outputs, and a recorded end-to-end demo. Include tests and an action log.
Decompresses CityJSON vertex integer coordinates using scale and translate factors.
Computes horizontal setback distance between building polygon and lot boundary.
Flags setback breaches less than the statutory 3.0m municipal buffer limit.
```json [ { "input": { "parcel_id": "LOT-441", "parcel_polygon": [ [ 0, 0 ], [ 20, 0 ], [ 20, 30 ], [ 0, 30 ] ], "building_id": "BLDG-441", "building_polygon": [ [ 4, 4 ], [ 16, 4 ], [ 16, 24 ], [ 4, 24 ] ], "min_required_setback_m": 3 }, "expected_output": { "compliant": true, "measured_min_setback_m": 4, "encroachment_detected": false, "status": "APPROVED" } }, { "input": { "parcel_id": "LOT-442", "parcel_polygon": [ [ 0, 0 ], [ 20, 0 ], [ 20, 30 ], [ 0, 30 ] ], "building_id": "BLDG-442", "building_polygon": [ [ 1.5, 4 ], [ 17, 4 ], [ 17, 25 ], [ 1.5, 25 ] ], "min_required_setback_m": 3 }, "expected_output": { "compliant": false, "measured_min_setback_m": 1.5, "encroachment_detected": true, "status": "VIOLATION_SETBACK" } } ] ```
Encroachment warnings are purely advisory; official boundary determinations require licensed land surveyor sign-off. Use mock external writes. Require human review before any real deployment.
Participation guide
Encroachment warnings are purely advisory; official boundary determinations require licensed land surveyor sign-off. Use mock external writes and human review.
How work is evaluated
Decompresses CityJSON vertex integer coordinates using scale and translate factors. Computes horizontal setback distance between building polygon and lot boundary. Flags setback breaches less than the statutory 3.0m municipal buffer limit.
Runnable source, pinned dependencies, setup commands, working interface, example outputs, recorded demo, tests, and action logs.
Challenge datasets
Public datasets, plus the private datasets you have access to.
How submissions are scored
These dimensions define what the evaluator checks and which criteria separate a passable run from a strong one.
Complete workflow
Extract 2D building footprints and LandUse parcel geometries from CityJSON dataset. Calculate minimum Euclidean distance between exterior building vertices and parcel limits. Compare computed distances against mandatory front, rear, and side setback regulations. Compile infraction summary highlighting encroaching vertices for planning authority.
Missing or incorrect.
Partly complete, with documented gaps.
Complete, with reproducible evidence.
Correctness and evidence
Decompresses CityJSON vertex integer coordinates using scale and translate factors. Computes horizontal setback distance between building polygon and lot boundary. Flags setback breaches less than the statutory 3.0m municipal buffer limit.
Missing or incorrect.
Partly complete, with documented gaps.
Complete, with reproducible evidence.
Review interface
Map viewer displaying parcel polygons, building bounds, setback violation buffers, and report log.
Missing or incorrect.
Partly complete, with documented gaps.
Complete, with reproducible evidence.
Safe execution
Encroachment warnings are purely advisory; official boundary determinations require licensed land surveyor sign-off.
This dimension contributes its full weight only when the submission satisfies the requirement. Partial credit is not awarded.
What you should walk away with
Extract 2D building footprints and LandUse parcel geometries from CityJSON dataset.
Calculate minimum Euclidean distance between exterior building vertices and parcel limits.
Compare computed distances against mandatory front, rear, and side setback regulations.
Compile infraction summary highlighting encroaching vertices for planning authority.
Reference links and supporting material
Synthetic CityJSON parcels generated from standard CityJSON v2.0 coordinate and LandUse schemas. Supplied starter examples are synthetic, not source extracts.
Challenge setup
Configuration summary for this challenge.
Challenge input
Input details are not configured.
Qdrant
Open-source vector database.
Evaluated output
No output checks are configured.
- Extract 2D building footprints and LandUse parcel geometries from CityJSON dataset. Calculate minimum Eucli...
- Decompresses CityJSON vertex integer coordinates using scale and translate factors. Computes horizontal set...
- Map viewer displaying parcel polygons, building bounds, setback violation buffers, and report log.
- 2 public reference cases
- 2 configured tools
Summary shows the first task, up to three tools, and up to three evidence items. Open the technical recipe to view all configured items.
View technical recipe
Configured tools
- Qdrant · Optional
- Qdrant · Optional
Evaluation contract
- Complete workflow · Weight 40
- Correctness and evidence · Weight 30
- Review interface · Weight 20
- Safe execution · Weight 10
Reference cases
- 2 public reference cases
Workflow tasks
No workflow tasks are configured.
Recipe freeze marker
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