Build a CityJSON 2.0 Material and Surface Reflectance Auditor
Inspect 3D city models in CityJSON 2.0 format to verify surface material definitions and appearance mappings. Calculate urban surface solar reflectance indices to identify heat-island mitigation opportunities across city districts.
What you are building
The core problem, expected build, and operating context for this challenge.
Inspect 3D city models in CityJSON 2.0 format to verify surface material definitions and appearance mappings. Calculate urban surface solar reflectance indices to identify heat-island mitigation opportunities across city districts.
Urban Sustainability Analyst
Load CityJSON 2.0 models containing Building objects and appearance material dictionaries.
Extract surface material associations, diffuse colors, and albedo properties across roof surfaces.
Compute average solar reflectance index for each building envelope and district cluster.
Generate a structured retrofit prioritization report for low-reflectance, high-heat roofs.
Heatmap visualization showing building roof polygons colored by albedo with filterable district tables.
Utilize standard CityJSON 2.0 sample models with appearance materials or mock CityJSON files with color arrays. Starter examples below are synthetic. They are not downloaded records.
CityJSON Extracts appearance object definitions, materials, and surface mapping indices from CityJSON 2.0 Section 6 and Section 1.
semantic-kernel, pydantic, matplotlib. Semantic Kernel orchestrates multi-step geospatial data queries and analytical synthesis prompts reliably. API-based hosted LLM for reasoning across geometric materials and urban thermal guidelines.
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.
Extracts material properties from CityJSON appearance object dictionaries.
Calculates solar reflectance values across building roof geometry surfaces.
Flags roofs with solar reflectance below 0.30 as candidates for cool-roof retrofits.
```json [ { "input": { "city_objects": { "bldg-north": { "type": "Building", "geometry": [ { "type": "MultiSurface", "material": { "roof": "dark_asphalt" } } ] } }, "appearance": { "materials": [ { "name": "dark_asphalt", "diffuseColor": [ 0.1, 0.1, 0.1 ], "reflectance": 0.12 } ] } }, "expected_output": { "audited_buildings": 1, "cool_roof_candidates": [ { "building_id": "bldg-north", "reflectance": 0.12, "recommendation": "High priority for high-albedo coating retrofit" } ] } }, { "input": { "city_objects": { "bldg-south": { "type": "Building", "geometry": [ { "type": "MultiSurface", "material": { "roof": "white_membrane" } } ] } }, "appearance": { "materials": [ { "name": "white_membrane", "diffuseColor": [ 0.85, 0.85, 0.85 ], "reflectance": 0.75 } ] } }, "expected_output": { "audited_buildings": 1, "cool_roof_candidates": [] } } ] ```
Outputs advisory urban planning analytics; does not alter municipal building permitting statuses. Use mock external writes. Require human review before any real deployment.
Participation guide
Outputs advisory urban planning analytics; does not alter municipal building permitting statuses. Use mock external writes and human review.
How work is evaluated
Extracts material properties from CityJSON appearance object dictionaries. Calculates solar reflectance values across building roof geometry surfaces. Flags roofs with solar reflectance below 0.30 as candidates for cool-roof retrofits.
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
Load CityJSON 2.0 models containing Building objects and appearance material dictionaries. Extract surface material associations, diffuse colors, and albedo properties across roof surfaces. Compute average solar reflectance index for each building envelope and district cluster. Generate a structured retrofit prioritization report for low-reflectance, high-heat roofs.
Missing or incorrect.
Partly complete, with documented gaps.
Complete, with reproducible evidence.
Correctness and evidence
Extracts material properties from CityJSON appearance object dictionaries. Calculates solar reflectance values across building roof geometry surfaces. Flags roofs with solar reflectance below 0.30 as candidates for cool-roof retrofits.
Missing or incorrect.
Partly complete, with documented gaps.
Complete, with reproducible evidence.
Review interface
Heatmap visualization showing building roof polygons colored by albedo with filterable district tables.
Missing or incorrect.
Partly complete, with documented gaps.
Complete, with reproducible evidence.
Safe execution
Outputs advisory urban planning analytics; does not alter municipal building permitting statuses.
This dimension contributes its full weight only when the submission satisfies the requirement. Partial credit is not awarded.
What you should walk away with
Load CityJSON 2.0 models containing Building objects and appearance material dictionaries.
Extract surface material associations, diffuse colors, and albedo properties across roof surfaces.
Compute average solar reflectance index for each building envelope and district cluster.
Generate a structured retrofit prioritization report for low-reflectance, high-heat roofs.
Reference links and supporting material
Utilize standard CityJSON 2.0 sample models with appearance materials or mock CityJSON files with color arrays. Supplied starter examples are synthetic, not source extracts.
Challenge setup
Configuration summary for this challenge.
Challenge input
Input details are not configured.
Semantic Kernel
Agent Systems · Agent Frameworks
Evaluated output
No output checks are configured.
- Load CityJSON 2.0 models containing Building objects and appearance material dictionaries. Extract surface...
- Extracts material properties from CityJSON appearance object dictionaries. Calculates solar reflectance val...
- Heatmap visualization showing building roof polygons colored by albedo with filterable district tables.
- 2 public reference cases
- 1 configured tool
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
- Semantic Kernel · 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
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Recipe freeze marker
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