Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 1/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment TechniquesChair of Engineering Surveying and Adjustment TechniquesChair of Engineering Surveying and Adjustment Techniques

Technische Universität Berlin

3D Building Information Efficiently Acquired and Managed

Lothar Gründig, Christian Clemen

Chair of Engineering Surveying and Adjustment TechniquesInstitute for Geodesy and Geoinformation ScienceTechnische Universität Berlin, Germany

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 2/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Motivation

Earthquake Risk Analysis and Disaster Management need accessible, reliable, actual and complete information on the situation.

Study area: Gathering 3d indoor models of the as-built situation efficiently.

Application: The 3d indoor model provides the spatial frame-work to the Building Information Model (BIM) used for risk analysis (e.g. structural statics) or rescue planning (e.g. escape route planning)

Motivation: Practice of indoor mapping….

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 3/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Motivation

What if…

…measurements have been forgotten …

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 4/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Motivation

What if…

…measurements disagree

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 5/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Motivation

What if…

…resulting walls do not aligne

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Motivation

What if typical mistakes occur during 3D as-build-documentation ?

Staff has to return to the building for re-measuring.

Mistakes remain undetected, thus the resulting building geometry is wrong.

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 7/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Motivation

sketch observe

adjustcalculate

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 8/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Motivation

sketch observe

adjustcalculate

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 9/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topological Redundancy

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Geometrical Redundancy

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 11/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Plane-based parameterisation

Geometry:x,y,z

Geometry:normal vector, rotation: nx, ny, nz

translational displacement: d

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Geometric normalization

Point based parameterization:412 nodes -> 1236 coordinate values

Surfaced based parameterization:104 d, 14 normal-vector values

Reduction: 91%The fewer “unknowns”the fewer measurements

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

The three main concepts of a surveying 3d data model

1. Observations and Constraints are considered to be the primary data Geometric properties of 3d entities are derived (estimated) quantities Redundant observations allow for checking and optimisationObservations are modelled stochastically

2. Surface-based (as apposed to point-based) parameterizationDecreases geometric redundancyThe fewer “unknowns” the fewer measurements

3. B-Rep Model with explicitly specified topologyTopologic entities (nodes, edges, faces, solids) are used for surveying reasons (identification) and for geometric calculations i.e. derivation of point co-ordinates

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 14/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Data Model - Workflow

Topology= Sketch

Geometry= Adjustment

(Parameter Estimation)

Observations/Constraints=

Measurement & Survey2

3

1

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch

The 3d-Designtool Google SketchUp is used for the sketch (Specification of the topologic primitives (node, edge, face) and topological structure)

Advantages:• Free Software • Easy to use for non-engineers• Extensible (Ruby-Scripts) • Open C/C++ API

Disadvantage:• Not as restrictive as need for “real” CAD Model• No surveying (measuring with geodetic instruments) capabilities

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch Topology = Sketch

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch Topology = Sketch

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 18/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch Topology = Sketch

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 19/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch Topology = Sketch

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 20/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch Topology = Sketch

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 21/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch Topology = Sketch

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 22/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch Topology = Sketch

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch

What do we have now?Topological structure of the (visible part of the) building

What do we have not?Topological consistent (CAD-like) modelCorrect Geometry (Model is a sketch!)

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 24/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch

What do we have now?Topological structure of the (visible part of the) building

What do we have not?Topological consistent (CAD-like) modelCorrect Geometry (Model is a sketch!)

Added user support for validation of topology

- each node is connected to at least 3 edges -

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 25/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch

What do we have now?Topological structure of the (visible part of the) building

What do we have not?Topological consistent (CAD-like) modelCorrect Geometry (Model is a sketch!)

Added user support for validation of topology

- each edge is connected to at least 2 faces -

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 26/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Topology = Sketch

What do we have now?Topological structure of the (visible part of the) building

What do we have not?Topological consistent (CAD-like) modelCorrect Geometry (Model is a sketch!)

Added user support for validation of topology

- each edge is an intersection of two non parallel planes -

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 27/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Data Model - Workflow

Topology= Sketch

Geometry= Adjustment

(Parameter Estimation)

Observations/Constraints=

Measurement & Survey2

3

1

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 28/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Adjustment – Integration to data model

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Measurement & Survey

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 30/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Measurement & Survey

Integration toData modelFunctional model (observation equation)GUI

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Measurement & Survey

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Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Soft Constraints (a priori)

Soft constraints are derived from the sketchA priori relative distances of parallel planesA priori relative angles between normals (in all combinations)

Why?Partial/selected improvement of geometric parameters

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 33/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Data Model - Workflow

Topology= Sketch

Geometry= Adjustment

(Parameter Estimation)

Observations/Constraints=

Measurement & Survey2

3

1

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 34/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Adjustment – Input and Output

Measurements and Constraints

Random variables

RedundantTopology

explicitly specified

Least-SquaresAdjustment

Plane Parameters 3d Model

Stochastically modelled

“best” result

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 35/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

Post Adjustment

Post Adjustment Statistics:Test the general goodness of fit and detect whether mistakes occur in observations or the functional/statistical model.Can help to transform 2d floor planes into geometrically valid 3d modelsCheck the geometric quality of existing models (KML, CityGML, IFC) with just a few (or more, redundant) measurements.

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 36/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

The three main concepts of a surveying 3d data model

1. Observations and Constraints are considered to be the primary data Geometric properties of 3d entities are derived (estimated) quantities Redundant observations allow for checking and optimizationObservations are stochastically uncorrelated

2. Surface-based (as apposed to point-based) parameterizationDecreases geometric redundancyThe fewer “unknowns” the fewer measurements

3. B-Rep Model with explicitly specified topologyTopologic entities (nodes, edges, faces, solids) are used for surveying reasons (identification) and for geometric calculations i.e. derivation of point co-ordinates

Christian Clemen - 3D Building Information Efficiently Acquired and Managed - TU Berlin - Slide 37/41

Department of Engineering Surveying and Adjustment TechniquesDepartment of Engineering Surveying and Adjustment Techniques

...Thank you for your attention !