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IFC-Based Definition of Geometry for

Buildings

Dr. Vladimir BazjanacLawrence Berkeley National Laboratory

Leader, IAI Technical Advisory Group

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2-D CAD: Professional Standard

1

20'

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

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2-D CAD: Professional Standard

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Future: 3-D CAD

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Types of Industry CAD Software

Vendor CAD software productCAD-based object

modelIndustry- based

object modelAutodeskAutodeskBentley SystemsGraphisoftNemetschek

AutoCAD 2000Architectural Desktop 2MicroStation TriFormaArchiGraph 6.5Allplan FT 15

YESYESYESYESYES

NONOT REALLY

A LITTLEYESYES

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CAD-Based Industry Applications

• Who in the industry needs the acquisition of Who in the industry needs the acquisition of geometry? Virtually everyone!geometry? Virtually everyone!• architectsarchitects• engineers (structural, mechanical, electrical, civil, fire engineers (structural, mechanical, electrical, civil, fire

protection, etc.)protection, etc.)• cost estimatorscost estimators• contractors and builderscontractors and builders• inspectors and code checkersinspectors and code checkers• building operators/engineersbuilding operators/engineers• facility manageresfacility manageres

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Geometry Performance Needs

• DimensionalDimensional• Perfect space enclosurePerfect space enclosure

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Industry Need for Interoperability

StructuralEngineer

Architect

CivilEngineer

HVACEngineer

BuildingOwner

ControlsEngineer

Facil itiesManager

Constr.Manager

Currently: fracturedflow of information

SHAREDPROJECTMODEL

StructuralEngineer

Architect

CivilEngineer

HVACEngineer

BuildingOwner

ControlsEngineer

FacilitiesManager

Constr.Manager

Future: all data availableto everybody at all times

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The Mechanism of Geometry Exchange

EXPRESSDefinition

Physical File

Client/Server

SDAI Database

Distributed (Interface)

Application

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Application Geometry Import/Export

IFC objectModel

IFC 1

application

IFC 2

IFC 3

IFC i

IFC i+1

IFC n

IFCprojectmodel

IFCtoolbox

definesclasses instances

reads & writesreads & writes

IFC-compliantmodule

non-IFC-compliant

data

IFC 1

IFC 2

Figure 2 - "Early-Binding" Toolbox Environment

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International Alliance for Interoperability

Mission:Mission:• To define, promote and publish specifications To define, promote and publish specifications for the Industry Foundation Classes (IFC) as a for the Industry Foundation Classes (IFC) as a basis for AEC Project information sharing basis for AEC Project information sharing through the project life cycle, globally, across through the project life cycle, globally, across disciplines and technical applicationsdisciplines and technical applications

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IFC Object Data Model Architecture

CostResource

GeometryResource

TopologyResource

GeometricModel

Resource

MaterialResource

MeasureResource

PropertyResource

ActorResource

ExternalReferenceResource

ApprovalResource

DateTimeResource

Repres-entation

Resource

ProfileResource

UtilityResource

Kernel

ProductExtension

ProcessExtension

ModelingAid

Extension

Shared BuildingElements

Shared BuildingServices Elements

Shared FacilitiesElements

Shared ManagementElements

Shared SpatialElements

ArchitectureDomain

HVACDomain

FMDomain

ConstructionManagement

Domain

ResourceLayer

Core & ExtensionsLayer

InteropLayer

DomainLayer

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The IFC Geometry Model

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IFC Views of Geometry

• Bounding boxBounding box• Attribute-drivenAttribute-driven• SolidsSolids

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STEP AP225: Types of Building Elements

• Structure/enclosure elementsStructure/enclosure elements• wallswalls• beamsbeams• columnscolumns• slabs, etc.slabs, etc.

• Building services elementsBuilding services elements• Fixture equipment elementsFixture equipment elements

• doors,doors,• windows, etc.windows, etc.

• SpacesSpaces• Simple digital terrain modelSimple digital terrain model

• planar faces as trianglesplanar faces as triangles

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*.ifc File#19=IFCPROJECTTEAMREGISTRY(());#20=IFCPROJECT('-1338121666',#2,(),(),(),$,#7,#19,#18,$,#17);#21=IFCREPRESENTATIONCONTEXT('-1338121665',.OUTLINE.,.PLAN.,1);#23=IFCCARTESIANPOINT((0.,0.,0.));#24=IFCAXIS2PLACEMENT3D(#23,$,$);#25=IFCCARTESIANPOINT((0.,0.,0.));#26=IFCLOCALPLACEMENT('-1338121663',$,#17);#27=IFCREFERENCEPOINT('-1338121662',#26,#25);#28=IFCLOCALPLACEMENT('-1338121661',#20,#24);#22=IFCSITE('-1338121664',#2,(),(),(),#28,$,$,$,.BUILDINGSITE.,(0,0,0),(0,0,0),0.,$,10000000000000.);#29=IFCLOCALPLACEMENT('-1338121660',#22,#17);#30=IFCBUILDING('-1338121659',#2,(),(),(),#29,$,$,$,.BUILDING.,4300.,379747479.8745677,1632914163460.641);#31=IFCRELCONTAINS('-1338121658',#2,(),.F.,.F.,#22,(#30),.SITECONTAINER.,.T.);#32=IFCCARTESIANPOINT((0.,0.,0.));#33=IFCAXIS2PLACEMENT3D(#32,$,$);#34=IFCLOCALPLACEMENT('-1338121657',#30,#33);#35=IFCBUILDINGSTOREY('-1338121656',#2,(),(),(),#34,$,$,$,.BUILDINGSTOREY.,0.,4300.,379747479.8745677,1632914163460.641);#36=IFCRELCONTAINS('-1338121655',#2,(),.F.,.F.,#30,(#35),.BUILDINGCONTAINER.,.T.);#37=IFCCARTESIANPOINT((28126.47648719469,9119.645385744449,0.));#38=IFCCARTESIANPOINT((28126.47648719469,9119.645385744449,4300.));#39=IFCCARTESIANPOINT((28126.47648719469,11111.65370838475,4300.));#40=IFCCARTESIANPOINT((28126.47648719469,11111.65370838475,0.));#41=IFCPOLYLOOP((#37,#38,#39,#40));#42=IFCSHAPEREPRESENTATION((#41),#21,.EXPLICIT.,$);#43=IFCSHAPEBODY('-1338121654',(#42),$);

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Geometry Data Exchange Issues

• File sizeFile size• Interfaces to the IFC object data modelInterfaces to the IFC object data model• MiddlewareMiddleware

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E+ Interoperable Environment

*.ifcfile E+E+client

CAD application

other CADapplication

other CADapplication

clientother CADapplication

other CADapplication

other applicationother application

non-IFCdata

IDF

ODF

otherapplication

otherapplication

client

IDF

ODF

middleware

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Contact Information

Dr. Vladimir BazjanacLawrence Berkeley National Laboratory

University of CaliforniaBerkeley, CA 94720

(510) 486-4092e-mail: vlado@gundog.lbl.gov

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Thank you!Thank you!

Questions?Questions?