A semantic-based framework for managing,
searching and retrieving 3D resources
Marios Pitikakis, CERETETH
Chiara Catalano, IMATI-CNR
www.cereteth.gr

What’s needed for sharing?
Feature extraction
Indexing
Metadata
While addressed successfully for text and 2D
content, the management of semantic 3D
shapes is still in its infancy
Content-based analysis and retrieval

What’s semantics?
Knowledge related to the geometry of the 3D
shape
Knowledge related to the application domain
in which the object is manipulated
Knowledge related to the meaning of the
object represented by the 3D model

To turn 3D shapes in semantic shapes
CG KT
o 3D shape analysis & o metadata and standards for
segmentation 3D annotation
o 3D object comparison & o ontologies (broad & narrow
classification domains)
o 3D scene understanding o formalization of workflows,
o smart 3D modelling tools functionalities
o 3D mark-up
 3D models representing not only shape but also
semantics
 3D media annotation tools (manual, automatic)
 intelligent virtual environments

Adding semantics to geometry
We have to extract and associate knowledge to
digital content
Shape analysis: extracts implicit info coded
into the geometry
Numerical values (e.g. volume, area, spatial
distribution, curvature)
Shape descriptors (structuring the shape)
Segmentation
geometry structure semantics

Semantic-driven segmentations
They captures semantically relevant features
automatically
what is relevant in the cultural heritage context?
IMATI segmentation methods for triangle meshes:
Fitting primitives
Reeb Graphs
Tailor
Plumber
They extract specific kind of knowledge suitable also
for virtual heritage

IMATI segmentation methods

Adding semantics to geometry
We have to extract and associate knowledge to
digital content and its subparts
Shape Annotation: it documents the shape
with contextual knowledge either manually or
automatically
geometry structure semantics

AIM@SHAPE approach
Ontology
Metadata
Geometry

ShapeAnnotator: general framework
Shape
A surface mesh
Abstracted
Shape
Shape A segmented mesh
CG Tools
Segmentation Plug-ins Annotator
Domain
An OWL ontology
Instance
Instance
Expert Knowledge Base

ShapeAnnotator: multi-segmentation
Pick the interesting features from different
shape segmentations
(b) Morse-based (c) Plumber (d) Fitting primitives

The ShapeAnnotator: ontology browser

The ShapeAnnotator: knowledge base

CH example….

AIM@SHAPE Digital Shape Workbench
Components
Ontologies
Shape repository
Tool repository
Pubblications
Glossary
Browsing
Search
By keyword
By semantics
By geometry
(DEMO)