Post on 13-Oct-2020
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 1
Berlin Institute of Technology
Department of Geodesy and Geoinformation Science
Plane Based Free Stationing for Building Models
Christian Manthe, Germany
21.05.2011
Chair of Geodesy and Adjustment Theory
Introduction
►Motivation
►Plane based building model
►Plane detection in point clouds
►Plane based free stationing
− Transformation parameter
− Corresponding planes
►Geometrical adaption
►Conclusions
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 2
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 2
Chair of Geodesy and Adjustment Theory
Motivation
3D Building Models are used to
►Construct buildings
− all entities are designed
− Geometry is errorless given
►Manage existing buildings
− Current description
− Model geometry should based on real measurements
►Planning of modifications or interior decoration
− The model geometry has to be sufficient comparing to
given tolerance values
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 3
Chair of Geodesy and Adjustment Theory
Motivation
Searched :
►Method to update the model geometry
►Quality control of building model (precision and reliability)
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 4
model
Point cloud
Plane based
representation
plane extraction
Plane based free
stationing
for transformation
and searching of
corresponding
planesplane set
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 3
Chair of Geodesy and Adjustment Theory
Plane based Building Model
Plane based representation
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 5
Geometry
Topology
Validation
problem
Chair of Geodesy and Adjustment Theory
Plane based Building Model
Building representations based on
►Solids (civil engineering)
►Divided spaces (surveying)
Validation in steps:
►Step 1: Separate validation
− Closed spaces or solids
− Aggregation of related entities to solve the Euler formula
v-e+f+2h-r=2 (vertices v, edges e, faces f, holes h, inner loops r)
►Step 2: Joined validation
− Nodes intersect by more then 2 planes
− Independent plane normal's more then 2
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 6
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 4
Chair of Geodesy and Adjustment Theory
21.05.2011 7
XML-file of a cuboid
Model of a cuboid
Nodes – Edges
Edges – Mesh
Mesh – Plane
Plane – Normal Vector
Normal Vector - Parameter
Geometry
Chair of Geodesy and Adjustment Theory
Plane Detection
Automated feature extraction in point clouds
►Relationship between points and planes is given (total station)
►Neighborhood of the points is given (laser scanning)
►without assumptions or advance information
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 8
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 5
Chair of Geodesy and Adjustment Theory
Plane Detection
Step 1: Segmentation (adjacent point groups)
►Storing the points in a kd-tree
►Create a space index with respect to a fixed number of points (cubed
subspace)
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 9
Chair of Geodesy and Adjustment Theory
Plane Detection
Step 2: Determination of planes
− Using Random Sample Consensus (RANSAC) paradigm
• To extract multiple instances
• Number of useful tries l depends on the failure rate f and the number
of planes k. (l=ln(1/p)*k2)
1. After l tries the best represented plane parameter are chosen
2. Adjustment (gives the parameter and stochastic information)
3. The assigned points were canceled for the next detection
− The procedure will run until k planes were extracted (subspace)
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 10
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 6
Chair of Geodesy and Adjustment Theory
Plane Detection
Step 3: Merging the local planes to a global plane set
►Use the F-Test to detect identical planes
►Using the index structure of the subspaces
At the end of the feature extraction
− A planes set is given
− Stochastic information is accessible for all planes in the plane set
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 11
Chair of Geodesy and Adjustment Theory
plane based free stationing
6/1/2011Christain Manthe - 12
model
Point cloud
Plane based
representation
plane extraction
Plane based free
stationing
for transformation
and searching of
corresponding
planesplane set
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 7
Chair of Geodesy and Adjustment Theory
plane based free stationing
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 13
11dnxF
vr=
plane 1cloud system
plane 2model system
1110 dxn plane −=rr
2220 dxn plane −=rr
txRx Fplane
rrr+=2
1d
1nv
2d
2nr
12 nRnvr
=
2220 dxn plane −=rr
22 )(0 dtxRn F −+=
rvr
2112 )(0 dtdnRn −+=
rrr
2122 )(0 dtdnn −+=
rrr
2210 dtnd −+=
rr
Estimation of the
Transformation parameter
Chair of Geodesy and Adjustment Theory
plane based free stationing
Semi-automatic matching of corresponding planes
1. Manual assignment of more than two corresponding planes
2. Calculation of the transformation parameter between the model
system and the point cloud system
3. Transformation of the plane set into the model system to find more
candidates for corresponding planes
4. Testing the candidates and extending the plane based model
5. Rerun step 1 – 4 until no more identical planes were found
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 14
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 8
Chair of Geodesy and Adjustment Theory
plane based free stationing
The plane based building model and its upgrad with respect to the
corresponding planes
►Each cloud plane is attributed with it transformation to the model
►For each plane it stochastic information is accessible
►Plan assignments are stored in a entity relationship model
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 15
Chair of Geodesy and Adjustment Theory
Geometrical adaption
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 16
model
Point cloud
Plane based
representation
plane extraction plane set
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 9
Chair of Geodesy and Adjustment Theory
Geometric adaption
New plane information is used to update the geometry
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 17
Example: cuboid updated with new normal vector parameter
Chair of Geodesy and Adjustment Theory
Conclusions
►Plane based representation of building models is useful to update the
geometry of an building model
►A method to extraction planes in point clouds with no advanced
information is implemented (plugin for Google Sketchup)
►After a feature extraction a plane based free stationing (registration)
can be used to update building geometry
►Because of the given stochastic information by the cloud planes
stochastic information for the model is accessible
►If the local precision of the model is no enough new observations can
be measured and used for updating the geometry without influencing
the model topology
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 18
FIG Working Week 2011
Bridging the Gap between Cultures
Marrakech, Morocco, 18‐22 May 2011 10
Chair of Geodesy and Adjustment Theory
21.05.2011Christian Manthe - Plane Based Free Stationing for Building Models 19
Thanks for your attention!