Welcome to the closing day of ARC ARCHEOS

George DrettakisREVES/INRIA, Sophia-Antipolis, France

ARC ARCHEOS

National funding for inter-group research– idea developed with J. Thollot and the

ERGA group in Grenoble (F. Letoublon)

– NPR research for archeology in an immersive VE context

– coordinated by REVES

General Goals

Bring together archeologists, historians and graphics, VE researchers– a small number of groups/people– specific projects (NPR/Argos)

Advance CG research for archeology– emphasis on NPR approaches– general rendering/representation issues

Achievements

Meetings and discussions– interdisciplinary meetings

core ERGA/ARTIS/ENS/REVES

– several external contributors Piérart, Pariente for Argos/archeology Deussen, Ostromoukhov on the NPR side

Very productive– good contacts have been established

CG Research

Canvas paper (Cunzi et al)– Graphics Interface 03 publication

CG Research

Crowd paper (Heigias et al)– Graphicon paper

CG Research

Watercolor rendering– Pascal Barla with Joelle Thollot

DEA (Master’s) – work continues as a Ph.D.

CG/VE Research

Discussion on Realistic vs NPR representations

CG/VE Research

NPR on a semi-immersive system– 6-month internship (Roman Bayon)– ported Raskar ’s algorithm to

workbench– first port of Canvas algorithm to

workbench– Interesting issues in 3D

Archeological Forums Poster at International Congress of

Classical Archaeology 2003 – presented by Isabelle Ratinaud and

Joelle Thollot

Archeological Forums

Seminar at Fribourg– Isabelle Ratinaud

Argos symposium at the EFA in Athens– Isabelle Ratinaud and Matthieu Cunzi– presentation of the canvas crowd and

VE demo work

Demos on the Workbench

virtual reconstruction of Argos Agora– reconstruction in Hellenistic Age– two hypotheses for the Tholos

mix of rendering styles– Raskar+crease object renderings

époques– classical and geometric periods

Closing Day

Morning– presentations of research results– demos on the workbench

Afternoon– roundtable of archeologists/historians

and CG/VE researchers

Enjoy...

Expressive and Realistic Renderings on a

workbench

Roman BayonGeorge Drettakis

REVES/INRIA, Sophia-Antipolis, France

Overall Goals

expressive rendering on a workbench– chose fast and simple solution

(Raskar)– integrate with existing software tools

canvas in stereo– try and adapt the subjective canvas

impression to a stereo context

Software Engineering

handling stereo– CAVElib

software engineering choices– REVES API - lab common API– SGI Performer-based solution

XP Extensible Scenegraph

developed at EVL and FHW– wrapper scene graph for SGI Performer– message handling and input events– extensible C++ classes

easy to add a new feature/rendering type

– allowed fast adaptation to bench– complicates more sophisticated uses of

OpenGL

Solutions adopted

REVESAPI– compatibility problems– scenegraph dependencies

native performer class– raskar renderer in a separate

Performer ”channel”– find crease lines in preprocessing

pass

Canvas

what are we doing ?– subjective effect, NOT the same thing– canvas inherently a 2D solution

straightforward port– shower glass effect i.e., canvas is

stuck on the screen or some other fixed point

Canvas in Stereo

First attempts– manipulate texture coordinates– use paralax and motion cues for

stereo effect– a different effect will result

choose parameters giving satisfactory subjective result

Demos

work with Alexandre Olivier-Mangon– Argos environments built in Maya– scripting done in XP

additional functionalities added to XP– Emmanuel Gallo (multiswitch,

transparency etc).– Davd Geldreich (Gamepad interface)

Tholos Demo

Hellenistic period– 6 buildings in the Agora– added houses based on Alix – added trees

point based rendering [Stamminger Drettakis

01]

– shadows for the Tholos perspective shadow maps [Stamminger

Drettakis 02]

Tholos Demo

Expressive rendering demo

Raskar for silhouette rendering precomputed crease lines

– simple color materials– painted sky dome

mix-mode rendering– actual stones textured/realistic

Expressive rendering demo

Epoques demo

geometric period– artifacts

first helmet/armor in Hellenic history vase

– simple houses classical period

– Agora was relatively empty

Issues for Demos

frame rate and scene complexity– intensified by multi-pass solutions

(Raskar) transparency

– help archeologists place objects can be a constraint

interaction tools– many more could be imagined

Future Work

Adapt different types of expressive renderings to stereo– stereo implies problems for

silhouette-based approaches– interesting effects could result, but

only practical tests can validate them Drawing styles are a nice form of

abstraction