annotating 3d content · agenda 1. motivation 2. image-based labeing of 3d content 3. enhanced...

Annotating 3D Content in Interactive, Virtual Worlds

Christine LEHMANN Jürgen DÖLLNER

Agenda

1. Motivation

2. Image-based Labeing of 3D Content

3. Enhanced Visibility Analysis

4. Smooth Transitions

5. Conclusions

Annotating 3D Content in Interactive, Virtual Worlds | Web3D 2013 | Christine LEHMANN

2

Foundations: What is Labeling?

Labeling algorithms are faced with a number of fundamental challenges including:

□ Find non-conflicting positions

close to labeled objects

in the view plane (label embedding)

□ Guarantee non-ambiguous assignments

□ Ensure readability of labels

Different Approaches for labeling

with different advantages :

□ Internal labels provide fast assocating

to labeled objects

□ External labels can be applied

to very small objects (small visible amount)


3

Example: Boundary Labeling (external)[Bekos et al.: „Boundary Labeling with OctilinearLeaders“, 2008]

Example: Street Labeling (internal)

Example: Google Maps


4

Example: Google Earth (1/3)


5



6

?



7

?

Contribution


8 ■ Our method enables attaching labels to

salient points and lines for internal label

placement

■ It uses visibility analysis to overcome

general labeling obstacles, most

important unambiguous label assignment

Use both internal and external labeling:

■ Apply internal and external labels

depending on visibility analysis

■ Enable transitions between external and

internal label placement

Example: Internal and External labels combined


9

Image-based Labling of 3D Content

■ Labels are placed exclusively on

visible areas of labeled objects

■ Visible pixels of 3D objects are

collected from the identity-map

(id-map)


10

Example: Internal Label Placement and External Label Placement with according id-maps.

Enhanced Visibility Analysisfor Labeling

■ From visible pixels, compute the distance transform and the normal field


11



12



13



14



15

Smooth Transitions


16 Labels switch from internal (with horizontal orientation) to external by

”walking” along the arrows (normal field).

Conclusions


17Image-based label placement:

■ Suitable for responsive systems and

interactive 2D/2.5D/3D systems

■ Easy integration into service-based

systems

Enhanced Visibility-driven

label placement:

■ Unambiguous label assignments

■ No time-consuming 3D geometry

analysis of labeled objects

■ Dynamic switching between internal

and external labeling

■ Simultaneous usage of external and

internal labeling based on visibility

analysis

Conclusions


18 Contact:

www.4dndvis.de

Christine Lehmann

[email protected]

Jürgen Döllner

[email protected]

Publications:

http://www.hpi.uni-potsdam.de/doellner/4dndvis/publikationen.html

This work was funded by the Federal Ministry of Education and Research (BMBF), Germany

within the InnoProfile Transfer research group "4DnD-Vis".

annotating 3d content · agenda 1. motivation 2. image-based labeing of 3d content 3. enhanced...

Documents