Kim, Sung-Ho
School of Computer, Information and Communication Engineering
Sangji Univ.
차례
증강현실의 개요
ARToolkit의 특징
ARToolkit Architecture
ARToolkit Structure
What does ARToolkit do?
How to install & setting up it?
Setting up ARToolkit
Coordinate Systems
Expanding the S/W
How to import a new VRML model
How to make your own marker
Interesting Links
References
증강현실의 개요
가상 현실(Virtual Reality)의 한 분야로 실제 환경에 가상 사물이나 정보를 합
성하여 원래의 환경에 존재하는 사물처럼 보이도록 하는 컴퓨터 그래픽스 기
법으로,“증대, 확대”라는 의미를 담고 있는 증강(Augmentation) 이라는 단어와
눈앞에 펼쳐진 실제 현실(Reality)이라는 단어가 합쳐진 합성어
어떤 특정한 환경이나 상황을 컴퓨터로 만들어서 그것을 사용하는 사람이 마
치 실제 주변 상황이나 환경과 상호작용을 하고 있는 것처럼 만들어 주는 인
간과 컴퓨터 사이의 인터페이스(Interface)
– 인공 현실(Artificial Reality), 사이버 공간(Cyber Space)
– 가상 세계(Virtual Worlds), 가상 환경(Virtual Environment)
– 합성 환경(Synthetic Environment), 인공 환경(Artificial Environment)
– 시뮬레이션 기술(Simulation Technology)
가상현실 : 현실 세계를 대체하여 창조된 새로운 환경
증강현실 : 현실 세계에 가상의 정보(객체)를 중첩함(Mixing)으로써 현실 세계
를 보충하여 사용자에게 보여 주는 환경
– 현실의 이미지와 가상의 이미지를 결합한 것
– 실시간으로 Interaction이 가능한 것
– 3D 공간 안에 놓인 것
증강현실의 개요 (계속)
증강현실의 요소 기술
– Marker Detection Technology
• 기준 좌표 역할을 하는 사각형의 마커를 인식하고 그 마커를 기준점
으로 하는 기술
– Markerless Tracking Technology
• Feature based Tracking
• 영상 내에서 특징 점들을 추출하고 이 특징 점들을 기반으로 좌표 계
를 추출
• 특징 점을 이용하기 때문에 사용자가 정의한 특정 패턴을 마커로 이
용할 수도 있다.
• 증강현실 기술에 있어서 가장 난이도 있고 점차 더 중요한 기술이 될
것으로 평가
ARToolkit의 특징
단일 카메라의 위치 / 방향을 추적한다
검은 사각형을 사용하는 추적코드는 간단하다
사각형의 Marker Pattern을 사용한다
간편하게 카메라 코드를 보정 할 수 있다
빠른 실시간 어플리케이션이다
무료로 배포되는 오픈 소스이다
PC CAM(화상카메라) , Visual studio 6.0이상, DirectX 9.0b 이상
ARToolkit의 Architecture
ARToolkit의 Structure
What does ARToolkit do ?
ARToolkit - Free tracking library
– Software library for building AR applications based on OpenGL
– Calculate the real camera position and orientation relative to physical markers
in real time
– 3D VRML support
– Software Library for vision-based AR applications
• Open Source(C language), multi-platform(SGI IRIX, PC Linux, PC
Windows)
– Overlays 3D virtual objects on real markers
• Uses single tracking marker
• Determines camera pose information (6 DOF)
– Includes utilities for marker-based interaction
– ARToolkit Website
• http://www.hitl.washington.edu/artoolkit/
• Limitations
– Monocular camera setup을 사용하므로 3D 측정이 불가능함
– Lighting condition과 Marker의 재질에 민감하게 반응할 수 있음
How to install & setting up it ?
Multiplateform library (Windows, Mac OS, Linux)
For Windows
– Download
• OpenGL
– GLUT
• DSVL(DirectShow Video Processing Library)
– Communication with the camera driver
• ARToolkit library
• OpenVRML
3D Graphics
• Libpng / jpeg
using OpenGL
• DXSDK
• msvcr71d.dll, msvcp71d.dll
– Building library
– Visual Studio 6 & Visual Studio .NET 2003
Image
VRML
ARToolkit
Audio
Video
Setting up ARToolkit
http://www.hitl.washington.edu/artoolkit/documentation/usersetup.htm
http://abekdh.tistory.com/9
http://www.mironae.com/1008
http://niceyth.springnote.com/pages/409596
Compile SimpleVRML with OpenVRML
Coordinate Systems
http://www.hitl.washington.edu/artoolkit/documentation/cs.htm
– Computer Vision Coordinate System
– Rendering Coordinate System
Expanding the S/W
\ARToolkit\bin\Data\object_data_vrml for simpleVRML.exe
Conceptual overview of the coherence between pattern, data and
image files




*.wrl : VRML models exported and ready for ARToolkit
*.dat : Tells ARToolkit how to scale and position your model
patt.anyName : The generated pattern definition
object_data_vrml : links .dat files to patterns
Expanding the S/W (Continued…)
The patterns to be recognized and their associated models are
specified in the Data/object_data_vrml file
This means that the VRML content associated with the pattern
"patt.hiro" is specified in the file "Wrl/bud_B.dat"
– #pattern 1
– VRML Wrl/bud_B.dat # Model 파일의 상대적 경로
– Data/patt.hiro
# pattern 파일의 상대적 경로
– 80.0
# pattern의 상대적 크기
– 0.0 0.0
# pattern 아래 방향, pattern 왼쪽 방향 이동 거리
The file line specifies the actual VRML file to be loaded, while the
next three lines set the translation, rotation and scale of the VRML
file from the pattern original
– Wrl/bud_B.wrl
– 0.0 0.0 0.0
# Translation - x,y,z from center of tracking
pattern
– 0.0 0.0 0.0 0.0 # Rotation angle + axis, eg 90.0 1.0 0.0 0.0
– 2.5 2.5 2.5
# Scale x,y,z
How to import a new VRML model
1. Copy your_file.wrl into the Wrl directory
2. Make a your_file.dat file and associate it with your_file.wrl by
typing Wrl/your_file.wrl on the first line.
– You may take a copy of one the existing .dat files and edit it to fit
your wrl file
– Place it in the Wrl directory
3. Make a new marker or use one that is not yet in use.
4. Edit the Data/object_data_vrml file by adding a new paragraph:
– #pattern 3
– VRML Wrl/your_file.dat
– Data/patt.sample1 -- Alternatively your new marker
– 80.0
– 0.0 0.0
How to make your own marker
To make it simple you can use the blankPatt.gif located in the patterns
folder of the ARToolkit installation
Draw your new pattern inside the black square
– http://www.roarmot.co.nz/ar/
How to make your own marker (Continued…)
The next thing you have to do is start the mk_patt.exe file located in
the bin folder. The file requires an input for the camera. You can use
"data/camera_para.dat". This is the default setting for the camera.
Position the camera right over the marker. You should be able to see
a red and green square around the pattern. This means that ARToolkit
has found your marker. Rotate the camera until the red corner is in
the upper left
How to make your own marker (Continued…)
Left click your mouse inside the viewing frame. Switch to the
command window and type the name of your pattern same as
“data/patt.mysamplepattern”
To use your new pattern you have to edit object_data_vrml
It should look something like this:
– #the number of patterns to be recognized
– 1
– #pattern 1
– VRML Wrl/bud_B.dat
– Data/patt.hiro
– 80.0
– 0.0 0.0
How to make your own marker (Continued…)
Explanation:
1. When you add a new set the new number of patters to be
recognized:
– #The number of patterns to be recognized
– 2
2. Add a new pattern number:
– #pattern 2
3. Insert reference to the DAT file of the VRML model to overlay the
pattern:
– VRML Wrl/maggie.dat
4. Insert reference to your new pattern. You can use any type of
filename
– Myfolder/mysamplepattern
5. Adjust the height of the overlayed object
How to make your own marker (Continued…)
Explanation (Continued…):
6. X and Y coordinates relative to the center of the pattern:
– 10.0 5.0
Then you should end up with something like this:
– #The number of patterns to be recognized
– 2
–
–
–
–
–
#pattern 1
VRML Wrl/bud_B.dat
Data/patt.hiro
80.0
0.0 0.0
–
–
–
–
–
#pattern 2
VRML Wrl/maggie.dat
Myfolder/mysamplepattern
105.0
10.0 5.0
Interesting Links
www.se.rit.edu/~jrv/research/ar/introduction.html
www.cs.unc.edu/Research/ProjectIndex/GraphicsImage.html
www.itk.ntnu.no/KIKS/demo/
www.csl.sony.co.jp/project/ar/ref.html
www.howstuffworks.com/augmented-reality.htm
http://cafe.naver.com/sigart.cafe
References
http://www.hitl.washington.edu/artoolkit/documentation/
http://jhseo.tistory.com/entry/ARToolKit-VRML-Programming
http://isa.umh.es/vr2/euron06/doc/labs/ARToolkit_for_Dummies.pdf
http://jhseo.tistory.com/135
http://makerfaireri.crowdvine.com/attachments/0000/4771/ARToolkit_Blender.pdf
http://old.uvr.gist.ac.kr/wlee/web/papers/2004/KHCI04_kkim_wlee.pdf
http://www.medien.ifi.lmu.de/lehre/ss09/ar/Installation_vom_ARToolKit.pdf
http://www.hitl.washington.edu/artoolkit/Papers
http://gekko.tistory.com/45
http://www.artoolworks.com/ARToolKit_Professional.html
http://www.artoolworks.com/support/library/ARToolKit_Professional
http://www.pragprog.com/titles/cfar/augmented-reality
http://jpyun56.wordpress.com/2010/01/18/augmented-realityapplication%EB%93%A4/
http://www.se.rit.edu/~jrv/research/ar/
http://makerfaireri.crowdvine.com/attachments/0000/4771/ARToolkit_Blender.pdf
http://cafe.naver.com/opencv