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Utilizing Virtual Environments in Construction Projects
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  1. Utilizing Virtual Environments in Construction Projects Author Lauri Savioja, Markku mantere, Iikka Olli, Seppo Ayravainen, Matti Grohn, Jyrki Iso-Aho Presenter K.S. Chiang

  2. Objectives • Introduce some basics of VR technologies, required software and hardware components • Brief introduction to EVE system and its application from architectural point of view • A case study: a construction project of a new lecture hall at the Helsinki University of Technology

  3. Introduction

  4. Virtual Reality Virtual Reality is used to simulate the nature world However, it still far from perfect illusion, quite convincing visual, aural, and haptic techniques to achieve this goal Few practical application of VR, Quite obvious application area is architectural visualization

  5. 3D product model The idea of product model is to combine separate drawings into one virtual building Benefits: • Applying virtual reality 3D model can support project decision • 3D model provides more information then traditional drawings • Construction project can maintain easily from start to hand-over • Good cost control and analysis

  6. Overview of VR technologies In the article of “Ultimate Display” in 1965 Ivan Sutherland introduced his visions of virtual environment Perfect virtual environment have four main challenges: • Look real • Sound real • Feel real • Respond real

  7. 1. Look real A virtual world look real must be carefully modeled • The surface of materials • Small details • Lighting • Body movement Creating a realistic environment • Models must obey the principles of physics • The view must be created in real-time

  8. 1. Look real Techniques: • HMD (head-mounted display) Two small displays, one for each eye • SID (spatially immersive display) A large display with special glasses for separating the images for each eye • Auto-stereoscopy Display stereoscopic images without using any special glasses HMD SID

  9. 2. Sound real For an immersive VR experience, 3D soundscape needs to be created, and it can enhance the sense of presence Techniques: • Binaural or multichannel technologies Control the sound signal in the entrances of listener’s ear canals, always fulfill with headphones using head-related transfer function (HRTFs) in HMD • Vector base amplitude panning (VBAP) Enable arbitrary positioning of sound sources Always use in multi-user situation

  10. 3. Feel real To make a virtual world feel real, the user must be able to touch virtual objects Haptic and force feedback is necessary Force feedback devices: • Joysticks • Steering wheels • gamepads

  11. 4. Respond real Respond to the user’s actions realistically, tracking the movements of body, head, hands and feet Techniques: • Mechanical tracking The body part is attached to a construction with sensor-fitted joints • Magnetic tracking some receivers for measuring either AC/DC magnetic field, then generated it by a transmitter • Hybrid system tracking Tracking system based on optical recognition, inertia and ultrasound

  12. Current VR technologies VR systems HMD

  13. EVE Experimental Virtual Environment system

  14. EVE • EVE is a virtual environment system at Telecommunications Software and Multimedia Laboratory (TML) at the Helsinki University of Technology (HUT) A 3x3x3 meters cube

  15. EVE - Hardware • Graphic hardware • Silicon Graphics (SGI) Onyx2 InfiniteReality2 8 x MIPS R10000 250 MHz CPU 2 GB Memory 2 IR2 Graphics pipes • 4 x ElectroHome Marquee 8500 LC Ultra projectors • CrystalEyes CE2 shutter glasses • Operating System: IRIX SGI Onyx2 computer

  16. EVE - Hardware • Audio hardware • Pentium 4 Linux-PC, StudI/O (2x ADAT I/O) • 2 x 8-channel D/A converters • 14 x Genelec 1029 active monitoring loudspeakers • Input devices • Mouse an keyboard of SGI computer • Mangetic tracker: Ascension MotionStar tracker • Fakespace V-Wand: Logitech Surfman radio mouse • 5DT DataGloves

  17. EVE - Application and Software For viewing various models in the EVE we need several different applications. So, we can integrate information like: • CAD model • Lighting solution • Computational fluid dynamics (CFD) stimulations • Acoustical models Software used in the EVE: • VRJuggler a platform for applications run in various VR systems “Code once, experience everywhere”

  18. EVE - Application and Software • OpenGL performer A high-level programming interface for rendering real-time 3D graphics. Typical uses: visualization, VR, CAD • Audio Software 1. DIVA (Digital Interactive Virtual Acoustics) system 2. Mustajuuri To reproduce the 3D sound of a real space artificially in real-time (audio processing)

  19. EVE - Application and Software • WolfViz convert computational fluid dynamics (CFD) data for proper visualization The software package contains three modules: 1. EnsightToVTK convert CFD data to a format readable by VTK 2. PreViz create visualization and stores it in OpenGL performer binary database format 3. PostViz used for displaying visualized data

  20. EVE - Application and Software • EveNavigator A viewing application which is implemented to replace former application of PostViz and HCNav. User can load a model and navigate in it. • VTK and vtkActorToPF Visualization toolkit for creating visualizations • PolyTrans A high quality 3D model and animation conversion software. It can be used both as stand-alone application and a 3DSMax plug-in

  21. EVE - A tool for the architect Tradition: • Traditional models are not perfect for architects • Pictures in 2D give little details and hard to have good understanding Virtual Environment advantage: • Virtual environment are easily understood • A product model into virtual environment can check any space of a project • Virtual Environment shows the things that the designer have not yet put enough thought into • Effective design and easy to manipulate

  22. EVE - A tool for the architect Interaction with other designer • Possible to discuss the basic concepts and logic of the project with designers Interaction with decision maker • Decision maker have enough power to make decision and suggestions Interaction with end-user • Designers get more information from end-user owing to have good understanding of the project

  23. Case Study

  24. Case Study: Construction of a new lecture hall The construction project was called Hall 600 at the Helsinki University of Technology (HUT) during 2001-2002 Parties involved in the project

  25. Models imported into EVE 1st model Preliminary model exported from the architect’s modeling software, ArchiCAD 2nd model More details representation 3rd model Much more realistic, but it was too complex Actural hall

  26. Geometry and Visual appearance • Rendering 3D graphics, OpenGL Performer • Adding lighting information, AutoDesk and 3DSmax • When the model was ready, converted and transferred into EVE, OpenFlight 14.2 from Multigen or PolyTrans • 1st model It was imported as a simple 3DSMax file • 2nd model It was most suitable for displaying in EVE • 3rd model It was more detailed and realistic, but it was too complex for graphics hardware. *Automated polygon reduction function of PolyTrans can decrease the model and make it smooth

  27. Computational fluid dynamics (CFD) simulations • Airflows in a room, causing by an air conditioning system, have an influence of the feeling to the users of the building • So that, the flow visualizations were presented at the same time for the realistic hall model Cross section illustrating velocity of airflow Particle flow model

  28. Computational fluid dynamics (CFD) simulations Isosurface illustrating velocity of airflow Iso-surfaces are arbitrary shaped surfaces, on which the magnitude of a chosen quantity is equal

  29. Acoustics • In a lecture hall, the acoustical properties are important, as the level of reverberation should be suitable for speech • The model was utilized in real-time dynamics auralization, in which user was able to move around the hall and listen to its acoustics in the EVE

  30. Examining model Examining model with air conditioning channels

  31. Studying model Three users in the EVE studying a detail in the Hall 600 model

  32. Conclusion of the case study • The product model and virtual environment proved to be a good combination • Alternative proposals and desired changes in the architectural design is easy to make • End-users can get a realistic impression of future spaces • 3rd model was disappointed to the designer since some information was lost in the polygon reduction process • Model was too complex to achieve in a sufficient frame rate

  33. The End Thank you

  34. Discussion • What is the advantage and disadvantage of EVE? • Do you have any suggestion to improve the EVE? • Should virtual environment be an essential part of construction projects?