STRICTANDAUTOMATICMAPPINGOFIFC-BIMMODELSINTOSEMANTICALLYENRICHED3DCITYGML BUILDING

MODELS(EXTERIORANDINTERIOR)1STINTERNATIONALIAGWORKSHOPONBIMANDGISINTEGRATION

25OCTOBER2017

RudiStouffs

IFCTO CITYGML

• Challenges

• Approach

• Scope

• Usecases

CONVERSION PROCESS

NativeBIM IFC CityGML

VirtualSingapore

Tekla

ArchiCAD

revit

AecoSIM

AB C D

A:VIRTUAL SINGAPORE CITYGML MODEL

• VirtualSingaporeisadynamic3Dcitymodelandcollaborativedataplatform.ThemodelandplatformwillbeunveiledduringtheWorldCitiesSummitinJuly2018.

Challenge1: Ensuretheresearchisdrivenbyuserneeds

A’:POTENTIAL USE CASES

• Housing&DevelopmentBoard(CentreofBuildingResearch)− energy− urbangreening− livingenvironment− waste&water− buildingtechnology

• UrbanRedevelopmentAuthority− housing− transport− economy− recreation− identity− publicspace

• SingaporeLandAuthority− 3Dcadastre&strata− planning− operations− riskmanagement

A’:POTENTIAL USE CASES

• Simulations− thermalcomfort(coolwalls)− energyconsumption(commonlighting,elevators)

− safeguardingwindcorridors− limitingnoise− solarphotovoltaics− greening− rainwaterharvestingandrecycling− urbanmobility

Challenge1: Ensuretheresearchisdrivenbyuserneeds

• Codecompliance− privacy− view

• Visualisation− operations(e.g.,refusedisposal)

B:NATIVE BIMBUILDING MODELS

• Singapore’sBuildingandConstructionAuthority(BCA)willmandatee-submissionsinnativeBIMformatfornewdevelopmentswithGFAmorethan5,000m2.NativeBIMe-submissionsmustbepreparedinaccordancewiththeprevailingCoP.

Challenge2:Workwithreal-worldnativeBIMmodels

Types Voluntary MandatoryArchitecture 19October2016 Secondhalfof2017C&SEngineering 1October2017 Secondhalfof2018MEPEngineering 1October2017 Secondhalfof2018

C:IFC4

• IFC4Addendum2publishedon15th July2016

• SelectionofIFC4asstate-of-the-artIFCstandard− nativeBIMmodelsasinput− focusonarchitecturalbuildingdata– includingfoundation(piling)

Challenge3: Demonstratetheconversionofmoreinformationthanhasbeenpreviouslyachieved– toenableautomaticcreationofsemanticallyenricheddatamodels

D:CITYGML V3.0

• CityGML v3.0isanongoingdevelopment− CoreModel− LevelofDetail(LOD)concept− improvedinteroperabilitywithotherrelevantstandards(IndoorGML,IFC,LADM)

• ApplicationDomainExtension(ADE)− GeoBIM (IFC)ADEforintegratingsemanticIFCdatainCityGML isinsufficientforourpurpose

Challenge4: TransitionfromCityGML v2.0toCityGML v3.0atsometimeduringtheproject

CONVERSION PROCESS

NativeBIM IFC CityGML

VirtualSingapore

Tekla

ArchiCAD

revit

AecoSIM

1 2

1:FROM NATIVE BIMTO IFC4

• Modelconsistency− noinitialweedingofunfavourableBIMmodels– aimtodetermineworkaroundsformodellinginconsistencies

− useofandtweakingofexistingexportfacilities toensureinclusionofallrequiredinformation

• Modelchecking− canaModelViewDefinition (MVD)beusedtoensureconsistency?

• Modelguidelines− suggestionsforamendmentstoBIMe-submissionCodeofPractice,basedonenhancedpracticalunderstandingofBIM-IFC-CityGML interoperabilitylevels

2A:FROM IFCTO CITYGML – SCOPE

• Startingpoints− IFC4− buildings– architecturalinformation(includingfoundation)− CityGML LOD3− exteriorandinterior(LOD4)

• Specificationrange− min:conversionofgeometricmodelcontent− max:completeandlossless− usecasesbased− configurable?

2B:FROM IFC TO CITYGML

• Kernel• Corelayer

− productextension

• Interoplayer− sharedbldg elements(wall,column,slab,stairetc.)

• Domainlayer− architecturedomain(windowsanddoors)− structuralelements(pilesandfootings)

• Resourcelayer− tobederivedfromcoreanddomainlayerwhatisneededtosupport

Imageadaptedfrom“IndustryFoundationClassesVersion4- Addendum2”,buildingSMART InternationalLimited.

2B:FROM IFC TO CITYGML

• Conversionofgeometriccontent− SweptSolid,Brep,CSG,…

• Typepropagationfrombuilding elementstosurfaces− walls,roofs,slabs,columns,beams,doors,windows

• Conceptualobjectssupportinginformationalusecases− spaces(physicalandlogical)

• Semanticrelationssupportingsimulationusecases− windowinawall,…− relationshipbetweenspacesandboundaries(CityGML v3.0)

• Relevantpropertiestosupportusecases− materialproperties:shader,reflectivity,transmittance,roughness− intendedusageofspaces− …

REMAINING POINTS

• FromIFCtoCityGML

• Theoreticalframework

PROJECT DETAILS

• Projectduration:May2017– April2019

• Funding:NRF2015VSG-AA3DCM001-008NRFandGovTech

• Researchcollaboration:OSI

• Collaboratoringagencies:HDB,BCA,URA

• Collaboratingvendors:Bentley,Graphisoft,Trimble,Autodesk

RESEARCH TEAM

• Principalinvestigators:− RudiStouffs(NUS– Dept.ofArchitecture)

− PatrickJanssen(co-PI)(NUS– Dept.ofArchitecture)

• Researchfellows:− HelgaTauscher(NUS)− FilipBiljecki (NUS)− JamesCrawford(OSI)

• Researchassistants:− ChenKok Kiong− AmolKonde

THANKYOU1STINTERNATIONALIAGWORKSHOPONBIMANDGISINTEGRATION

25OCTOBER2017

RudiStouffs