{"guid":"b55fbb53-3993-525c-8296-d1984573c4b5","title":"Floor plan extraction from digital building models","subtitle":null,"slug":"state-of-the-map-2022-academic-track-19570-floor-plan-extraction-from-digital-building-models","link":"https://2022.stateofthemap.org/sessions/ZUXTN8/","description":"As part of a larger endeavour to make floor plan representations from building models available for indoor map and navigation services, we study the integration of  IFC and OSM.\n\n# Introduction, background, motivation\n\nOfficial geo data is increasingly published not only in the form of 2D maps,\nbut also in 3D, mainly as city models in CityGML. Usually the outer shell of\nbuildings is captured in such models, but they may also involve more intricate\ndetail. Even more detailed building models are generated during the planning\nprocess for new buildings and renovations. These are nowadays produced in\ndigital form, archived in as-built phase by owners and operators for the life\ntime of a building and, in the future, may even be required to be submitted for\nbuilding permits.\n\nAt the same time there is an increasing public interest in detailed information\nabout public and semi-public interior spaces, for example about their\naccessibility, localization of barriers or targets (e.g. contact persons in\npublic administration, shops in malls, booths on fairs, markets or larger info\nevents, departments or hospital wards) or resources (e.g. books in libraries,\ncharging stations, fire equipment or defibrillators) or to get a first\nimpression in advance (e.g. virtual open day). The interest and the points of\ninterest may be temporary or permanent.\n\nSince the context of creating and capturing geo data and building data is\nfundamentally different, there is hardly any integration. Indoor data for maps\nand navigation models is manually captured or at best derived in undocumented\nmulti-step semi-automatic workflows.\n\n\n# Aim and purpose of the study\n\nThe project \"Level Out\" sets out to develop automated methods and services to\nmake detailed indoor data from digital building models selectively available\nfor the population of city models, map and navigation services  (in the form of\n2,5 D floorplans).\n\nTowards this end, we are developing a platform to check building models whether\nthey are suitable and contain required data, extract selected and simplified\nindoor data and convert it into various formats: CityGML LOD0 (Indoor),\nIndoorGML and OSM Indoor.  As input we rely on data in the format IFC (Industry\nFoundation Classes), the most widespread standard format for digital building\nmodels.  Indoor OSM, in particular geometry with Simple Indoor Tagging, is one\nof the various extraction targets. The data created may not be directly fed\ninto OpenStreetMap, but serve as a viable base for further mapping.\n\nThere are already older solutions, e.g. BIMServerOsmSerializer\n(\u003chttps://github.com/BIMDataHub/BIMServerOsmSerializer\u003e), which are only built\nfor a version of IFC, which has been a long time standard version, but\ncurrently approaches towards its end of life: IFC2x3.  There are also solutions\nunder active development, e.g. the JOSM plugin \"Indoor Helper\"\n(\u003chttps://wiki.openstreetmap.org/wiki/JOSM/Plugins/indoorhelper\u003e), which,\nhowever, lack some general approach on the IFC side and coverage of the\nheterogeneous options to represent geometry in the IFC schema.  With this\nresearch and development we aim to provide a workflow and software to\nsystematically access floorplan data in IFC.\n\n\n# Methodology\n\nWe start from both ends of integration by looking at the detailed structures of\nthe source and target models in parallel.\n\nFrom the group of target models, we derive a common model, which will have, at\nbest, near-trivial mappings to OSM Indoor, CityGML, IndoorGML. Although not\nstrictly necessary for the IFC-to-OSM conversion case or any other bilateral\nintegration, the intermediate model will not only allow to tackle integration\nof IFC with multiple targets besides OSM, but also integration of OSM with\nmultiple sources besides IFC.\n\nNext, we identify relevant information in the source model. IFC exposes a wide\nvariety of geometry modelling constructions from CAD software, mainly following\nthe modelling paradigm of constructive solid geometry (CSG). So far, we found\nthe following principle representation options:\n\na) Direct floorplan representation in 2.5D: Here we have 2D representations\n   located in 3D space, usually located at the level of the floor finish for a\n   particular storey. There are two versions to be distinguished: space\n   boundaries versus abstract representations of space-defining elements.\n\nb) Extraction from CSG: Spaces (as well as constructive elements) are often\n   represented as solids resulting from extrusion of a planar shape. If extruded\n   in z-direction, the base shape can be extracted and used as 2.5-D\n   representation.\n\nc) Projection onto floor level: If the geometry is not in CSG-form with\n   extrusions, but in BREP (boundary representation), then projection followed by\n   a simplification of the projection result is a possible way to extract.\n\nIn addition to the geometric elements, there are semantic elements connected to\nthe geometry that are connected themselves and can be used to charge the\ngeometric model elements with meaning. Depending on the geometry extraction\nmethod, correlation and consideration of semantic elements is more evident or\ncomplicated - hence possible to different degrees. The paper will discuss these\nimplications.\n\nAfter identification of the relevant entities, we are developing a three stage\nprocess for the actual population of target models from IFC.\n\n1. Building model enrichment: Information that can be represented in IFC will\n   be played back to the building model instead of being promoted to the generic\n   model only.\n2. Building to intermedite model: This essential step is coved with a flexible\n   rule-based mapping.\n3. Intermediate model to target models: Following a careful design of the\n   generic model, this step should be simple.\n\nWe are testing the processes with data from public buildings, two sets of\nuniversity campus buildings as well as one newly built municipal administration\ncentre. From assessment of the original building data, we will also develop\nmodelling and export guidelines for BIM software. As far as possible, the demo\ndata will be made available publicly as open data. More important, the\nconversion procedures will be published open source and a respective conversion\nservice will be offered online.\n\n\n# Discussion\n\nIn summary, our work provides practical benefit in terms of tools to support\nthe mapping process as well as a scientific contribution in terms of spatial\ndata integration and expert involvement via domain-specific languages.\n\nThe practical benefit of the conversion seems obvious: Building owners can\npublish data of their publicly accessible spaces to help with volunteer mapping\nwork. In the future we will also tackle update, checking and comparison with\nexisting OSM indoor data.\n\nScientific contributions are also made in different ways: First, an application\nscenario for the OGC Indoor Feature Model is provided and - interesting for the\naudience of this conference - evaluation of how OSM data fits with the\ngeneralized model. Further, we explore methods for flexible data integration\nwith domain specialist and expert community involvement. Finally, but beyond\nthe scope of this conference, the applicability of integration methods for\nbidirectional integration with  multiple sources and targets via intermediary\nformats is evaluated.","original_language":"eng","persons":["Helga Tauscher","Subhashini Krishnakumar"],"tags":["sotm2022","19570","2022","OSM","OpenStreetMap"],"view_count":99,"promoted":false,"date":"2022-08-21T14:05:00.000+02:00","release_date":"2022-10-14T00:00:00.000+02:00","updated_at":"2026-01-26T01:00:07.569+01:00","length":319,"duration":319,"thumb_url":"https://static.media.ccc.de/media/events/sotm/2022/19570-b55fbb53-3993-525c-8296-d1984573c4b5.jpg","poster_url":"https://static.media.ccc.de/media/events/sotm/2022/19570-b55fbb53-3993-525c-8296-d1984573c4b5_preview.jpg","timeline_url":"https://static.media.ccc.de/media/events/sotm/2022/19570-b55fbb53-3993-525c-8296-d1984573c4b5.timeline.jpg","thumbnails_url":"https://static.media.ccc.de/media/events/sotm/2022/19570-b55fbb53-3993-525c-8296-d1984573c4b5.thumbnails.vtt","frontend_link":"https://media.ccc.de/v/state-of-the-map-2022-academic-track-19570-floor-plan-extraction-from-digital-building-models","url":"https://api.media.ccc.de/public/events/b55fbb53-3993-525c-8296-d1984573c4b5","conference_title":"State of the Map 2022","conference_url":"https://api.media.ccc.de/public/conferences/sotm2022","related":[],"recordings":[{"size":22,"length":319,"mime_type":"video/webm","language":"eng","filename":"sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_webm-hd.webm","state":"new","folder":"webm-hd","high_quality":true,"width":1920,"height":1080,"updated_at":"2022-10-14T20:56:45.784+02:00","recording_url":"https://cdn.media.ccc.de/events/sotm/2022/webm-hd/sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_webm-hd.webm","url":"https://api.media.ccc.de/public/recordings/63026","event_url":"https://api.media.ccc.de/public/events/b55fbb53-3993-525c-8296-d1984573c4b5","conference_url":"https://api.media.ccc.de/public/conferences/sotm2022"},{"size":10,"length":319,"mime_type":"video/webm","language":"eng","filename":"sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_webm-sd.webm","state":"new","folder":"webm-sd","high_quality":false,"width":720,"height":576,"updated_at":"2022-10-14T20:56:02.902+02:00","recording_url":"https://cdn.media.ccc.de/events/sotm/2022/webm-sd/sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_webm-sd.webm","url":"https://api.media.ccc.de/public/recordings/63025","event_url":"https://api.media.ccc.de/public/events/b55fbb53-3993-525c-8296-d1984573c4b5","conference_url":"https://api.media.ccc.de/public/conferences/sotm2022"},{"size":4,"length":319,"mime_type":"audio/mpeg","language":"eng","filename":"sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_mp3.mp3","state":"new","folder":"mp3","high_quality":false,"width":0,"height":0,"updated_at":"2022-10-14T20:52:30.443+02:00","recording_url":"https://cdn.media.ccc.de/events/sotm/2022/mp3/sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_mp3.mp3","url":"https://api.media.ccc.de/public/recordings/63022","event_url":"https://api.media.ccc.de/public/events/b55fbb53-3993-525c-8296-d1984573c4b5","conference_url":"https://api.media.ccc.de/public/conferences/sotm2022"},{"size":7,"length":318,"mime_type":"video/mp4","language":"eng","filename":"sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_sd.mp4","state":"new","folder":"h264-sd","high_quality":false,"width":720,"height":576,"updated_at":"2022-10-14T20:51:15.094+02:00","recording_url":"https://cdn.media.ccc.de/events/sotm/2022/h264-sd/sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_sd.mp4","url":"https://api.media.ccc.de/public/recordings/63021","event_url":"https://api.media.ccc.de/public/events/b55fbb53-3993-525c-8296-d1984573c4b5","conference_url":"https://api.media.ccc.de/public/conferences/sotm2022"},{"size":13,"length":318,"mime_type":"video/mp4","language":"eng","filename":"sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_hd.mp4","state":"new","folder":"h264-hd","high_quality":true,"width":1920,"height":1080,"updated_at":"2022-10-14T20:48:05.291+02:00","recording_url":"https://cdn.media.ccc.de/events/sotm/2022/h264-hd/sotm2022-19570-eng-Floor_plan_extraction_from_digital_building_models_hd.mp4","url":"https://api.media.ccc.de/public/recordings/63018","event_url":"https://api.media.ccc.de/public/events/b55fbb53-3993-525c-8296-d1984573c4b5","conference_url":"https://api.media.ccc.de/public/conferences/sotm2022"}]}