Developing a VR System. Mei Yii Lim

Transcription

1 Developing a VR System Mei Yii Lim

2 System Development Life Cycle - Spiral Model Problem definition Preliminary study System Analysis and Design System Development System Testing System Evaluation Refinement

3 Case Study: MY Virtual Graffiti System

4 Introduction graffiti - Greek word graphein Modern graffiti - New York, tagging using water resistant marker Today - using aerosol spray Rude, humorous, political or constituting vandalism and is generally illegal

5 Problem Objectives What do you aim to achieve? Solution to the problem of illegality Preserves and documents art works Virtual spray on virtual buildings Flexibility and natural interaction Realistic reproduction of the spray User-friendly and intuitive interface

6 Problem Definition

7 Problem Definition Define the problem you are trying to solve What are the major issues?

8 Project Benefits What are the benefits of the project? Why is it so important? Expression of opinions, creativity lawfully Coping with society s problems London councils - 13m and graffiti committee - 100m spent annually on cleaning up graffiti New type of art, uncover hidden talent

9 Project Management Project scheduling Divides work into smaller chunks - Gantt Chart Risk Analysis Degree of uncertainty or potential problems Eg. lack of knowledge, inappropriate or difficult to use interaction devices, simulation algorithm, underestimation of time

10 Project Management Risk Planning continued Best way for project with users as target - involve them Trial and error Project schedule must be realistic

11 Preliminary Study

12 Literature Review Find out the state-of-the-art Who has done what What can be improve What should be avoided

13 Literature Review of MYVG Eschler & Stricker 03 (Fraunhofer IGD) projection filled totally by a 2D wall Dave Pape - Vandalism alter existing artworks, 3D paintings and sculptures Lang Virtual Graffiti Painter and Light bombing MobSpray (mobile application)

14 System Analysis

15 System Analysis Understand the requirements of the system you are going to develop Determine what is to be accomplished To ensure successful system development Human Computer Interaction concepts

16 Rapid Iterative Prototyping Offers the best approach for system which accurate requirements can not be defined at its early stage Prototype a mechanism for identifying the actual requirements Iterative and corrective cycle

17 Rapid Prototyping Development Cycle

18 Requirements Elicitation Fact-gathering active manipulation of conditions or passive observation of people Researching and reviewing existing documents Individual interviews Mailing list Observation demonstration from experts Questionaires - evaluation

19 Analysis with Justification Every choice must be justified Why a particular device or methodology is chosen and not the others?

20 Analysis Result of the MYVG system

21 MY Virtual Graffiti System CAVE Environment Graffiti using VR technologies 2 sensor gloves (pinch gloves) sensors

22 CAVE

23 MY Virtual Graffiti System Space Orb 360º (6 degree of freedom) Tracking system Dummy spray can with sensor Stereo glasses

24 Object-Oriented Model Use cases scenarios of usage Analysis model subsystems of the end product

25 System Requirements Specification Hardware requirements Software requirements Functionality description Non-functional requirements Interface specification Design constraints System validation and verification criteria

26 System Design

27 System Design How to accomplish the proposed functionality? How are all the VR devices linked together? Representation of the system

28 Architectural Design UML class diagrams - shows all available classes

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30 Architectural Design Object-relationship model static model, reflects the object classes and their relationship

31 Architectural Design State diagram dynamic model Describes the behavior of the system, events

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33 Architectural Design Sequence diagram illustrate each significant interaction between objects

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35 Algorithm Design Pseudocode description of the program Example a method to create scene METHOD createscene char*(filename) returns pfscene* Generate scene state Add lighting Set traversal mask Load file RETURN scene END

36 Scenegraph

37 User Interface Design A useful system with a poor user interface = non-functional system HCI golden rules Know the user population Reduce cognitive load Engineer for errors Maintain consistency and clarity

38 WELCOME TO VIRTUAL GRAFFITI! SPRAY MODE BUTTON A / LEFT PINKIE CLEAR BUTTON B SAVE BUTTON C / LEFT MIDDLE NAVIGATE BUTTON D, PS / RIGHT INDEX RESET BUTTON E EXIT BUTTON F CLOSE MENU RIGHT PINKIE

39 SPRAYING MODE SPRAYING RIGHT MIDDLE COLOUR LEFT MIDDLE NOZZLE LEFT RING MAIN MENU LEFT PINKIE NAVIGATE RIGHT INDEX CLEAR RIGHT RING / BUTTON B CLOSE MENU RIGHT PINKIE

40 3D icon that appears while spraying Denote the size of the nozzle Denote the color of the nozzle

41 System Development and Testing

42 System Development Programming Example of Challenges Format incompatibility Incorrect hit points Correct Ray Plane A Bounding box

43 Number of rays Single ray Multiple rays

44 System Testing Tedious but essential for quality assurance Formal technical review Unit testing Integration testing

45 Risk Monitoring Throughout the whole life cycle to ensure that everything is under control Users opinions were checked Project progress was monitored

46 System Implementation and Evaluation

47 System Implementation Putting the system into operation Prototyping approach implementation is parallel with the development and testing phases

48 System Evaluation Acquire feedback for eventual improvement Formative evaluation usability evaluation Can be repetitive Each evaluation process serves as guide for changes in subsequent iterations

49 Example Initial Evaluation Half a dozen subjects Bar Chart Representing Result of Initial Evaluation Engagement to environment Interaction devices Menus Commands Rating Spraying action Navigation Spray paint simulation Speed of adjustment Real-time response Comfortable interaction Resemblance to real graffiti 0.00 Evaluation Attributes

50 Refinement Menu shift and simplification User manual was provided More flexible interaction Space Orb or pinch gloves Dummy spray can Allow deactivation of menu Bigger paint particles for wider coverage

51 Comparison Between Initial Evaluation Result and Final Evaluation Result Final System Evaluation Twenty subjects Rating Engagement to environment Interaction devices Menus Commands User manual Spraying action Navigation Spray paint simulation Speed of adjustment Real-time response Comfortable interaction Resemblance to real graffiti Initial Evaluation Final Evaluatian Evlauation Attributes

52 Conclusion and Future Work

53 Achievements On schedule Improvement of skills Expansion of knowledge Chance to experiment with VR devices

54 Lessons Learned and Experiences Every development cycle should account for unexpected events Eg. Tools unavailability, lack of knowledge, system failure, power failure

55 Future Enhancements Wireless and pressure sensitive devices More attractive and user-friendly menu entails more extensive user involvement Collision detection and sound feedback

56 The System in Action

57 Further information _DISSERTATION.htm