Final Report - Tanos.co.uk
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1. e 5 Call 2 onward as a function recursively giving the top left quarter as the new area e 6 Call 2 onward as a function recursively giving the top right quarter as the new area e 7 Call 2 onward as a function recursively giving the bottom left quarter as the new area e 8 Call 2 onward as a function recursively giving the bottom right quarter as the new area This algorithm is recursive Changing line 2 to a higher area will decrease the resolution of the landscape and speed up the algorithm 13 3 4 4 Dynamic land colour A uniform green landscape would be uninteresting The landscape colour is calculated from the gradient at each surface Each point s colour is calculated separately To find the gradient at a point on the landscape two neighboring points in the x and z directions are found and the change in y for both of the points is recorded Both of the gradients are calculated and averaged This gradient value is then used to calculate the ratio between the two landscape colours On surfaces with a gradient of 0 flat ground the surface is coloured a dark green As the gradient increases the ratio of dark green to light brown changes so that vertical slopes such as cliffs have a light brown colour The point gains a mixture of these two colours and OpenGL blends between these 3 5 File Converters 3 5 1 ASC PC and OBJ Model import Converters have been added to convert ASC PC and OBJ files into a generic mode2. A forest of identical trees for example Primary objectives of the project Multi user 3D environment It is a complaint of some that chat rooms and instant messaging are a cold medium as users do not receive the same kind of emotional response as they have when communicating with the person face to face When this is not possible allowing many users to explore a shared world and meet each other helps to build community and provides a stimulating atmosphere Users will be able to adapt their surroundings to their desires and these changes will be kept even when they leave the world Multi platform environment In the main access to 3D environments have been the preserve of the Windows user Enabling the client program to run on multiple operating systems will allow users of Windows Linux Unix Mac and Solaris for example to explore the environment and communicate with each other Unicode character set support At the time of writing the author can find no web based communications tool that supports Unicode characters It is possible to download spe cialised instant messaging software with support for Unicode characters but some corporate and academic networks do not allow their users to install software on their computers Secondary objectives of the project User customisation 1 4 1 4 1 Allowing users to modify the world they inhibit allows a more interesting environment to arise Many people are interested in sh
3. A 3See Figure 3 in the pictorial appendix for a diagram of this 12 Where H A is the height at X on tile A The distances to the centre of A and to the centre of B are normalised so that they sum to 1 3 43 Goo algorithm Tiles used for the creation of the vast landscape are generated with the Goo algorithm One such tile is shown in Figure 2 of the pictorial appendix The Goo algorithm takes a seed as an input Given the same seed the same tile will be generated The Goo algorithm seeks to create a natural looking landscape shape over a square tile Goo generates the heights of each of the verticies of the tile Other stages of landscape generation such as blending and colouration are added later The parameters given to the goo algorithm are e Dimensions of tile to be generated top left width height e Minimum and Maximum heights of the landscape e Seed for random number generator It works as follows e 1 4 random numbers within the height range are generated then applied to the 4 corners of the given area e 2 If the area to be generated is 2x2 then end this function e 3 Of the corner s heights find the lowest and highest in the area e 4 Generate a random number between these ranges and apply it to the following points i Middle 4 ii Two on left middle and 2 on right middle iii Two on top middle and 2 on bottom middle At this point the area is blank apart from 12 coloured points
4. a good idea this feature shall be added later The radar is not clear This remark was aimed at the grey relief map drawn under the radar Radar was changed to be transparent and only show coloured points at objects in the scene 23 The points on the radar are too small The points were doubled in size given more contrasting colours and a command was added to allow the user to manually set the point size Feedback Many users commented on the stars during the night and one user liked the environment because it was Less linear When asked if people would just play in the 3D environment and not use the chat one user said It s most amusing with chat you can make up scenes with friends One student remarked that it was annoying that the multi player games that he played forced him to write in English letters referring to the act of transliterating the pronunciation of foreign phrases into roman characters The environment has been running online for several months only being reset when the server is changed to a new version Despite no online documentation the users have picked up the interface quickly and the online environment now holds many areas of interest such as a dinosaur farm a long tunnel and a small tank battle 4 6 User Interface Feedback Due to its simplicity the user interface was quickly understood and used without difficulty The comments made on the radar were the only concerns Commands to change the
5. a number of users tried the software their familiarity with computers was varied Feedback was be requested from all participants High level features of the program such as multi user support are also discussed 4 1 Module testing Due to the tree like structure of dependencies in the Applet and Server module testing was made simpler as the classes that had no dependencies such as the ProtocolHelper class could be tested individually In the event of an incorrect result the source code of the class was examined to find the source of the error and edited to fix it Once these classes were shown to be correct the classes one step up the tree could be tested because their dependencies were shown to be correct and thus all errors that occurred would have occurred in the class being tested An important dependency to remember is that of the client server system some functions output involves sending data out or acting on data that has been received As well as creating test harnesses for class testing telnet was used to test some features of the server by creating sample protocol lines for it to process A simple Java server was constructed to test the socket output of the clients Cmd Thread and ObjDownload Thread 5See Figure 7 in the pictorial appendix 6See Figure 8 in the pictorial appendix 19 The applet has been tested for data that would be expected to be sent For computer to computer communication the test inputs include
6. as light as possible This allows a much higher number of users before the server becomes unresponsive Data transfer is small because the client is sent location data and does all the processing itself 4 4 User Testing User Interface testing is part of module testing separately however it is impor tant also to see how users adapt to the User Interface changing the design to make the application easier to use may be required Module testing alone does not test ease of use 4 4 1 Nickname selection When a user first loads the applet they are presented with nick written in the input box Typing their chosen nickname after this and pressing enter sends 20 a request to the server to set their nickname to this new value A variety of nicknames were tested Chosen nickname Result Correct result No text Refused Yes Three spaces Refused Yes Jonathan Valid Yes ABCDE Valid Yes Sakura written in Japanese Hiragana Valid Yes Zhongwen written in Chinese Hanzi Valid Yes 50 character nickname in Roman characters Valid Yes not ideal Nickname with Katakana and Roman characters Valid Yes Result Meanings e Refused The nickname input was invalid The new nickname is not used and the user is sent the message You are currently a Guest Sign in to chat To sign in type nick lt your nickname gt e Valid The nickname is valid and is set as the user s nickna
7. object no methods to hold location rotation Unique Identifier and URL of each model instance in the world Used within the WorldDB class sCmdThread There is one sCmdThread for each client connected to the server This class processes the commands and chat messages sent from its client and sends commands and chat messages to the client when required Changes to the world near to the user are sent to the client serverCmd This class manages messages chat and command that are sent to and from the clients This class listens for new connections and creates sCmdThread threads to deal with them This class broadcasts chat messages to all other clients This class initialises the WorldDB object serverObj This class manages the file proxy system This class listens for new connections and creates sObjThread threads to deal with them sObjThread This thread allows the proxy of files The client requests a file by its URL and this class will either download and send the file to the client or inform the client that the file cannot be downloaded timeOutCheck Sends periodic messages to check whether the client is still connected which the client is expected to reply to When there is no response the client is given 3 warnings before being disconnected WorldDB Stores every instance in the world e g avatars huts trees Al lows objects to be added and deleted from the world Initialises the world to contain 40 trees two houses and a signpos
8. was started but this support seems unreliable and the author has had limited success with non roman character input VRML Homesteads VRML Homesteads are VRML scenes that are connected by hyperlinks The scenes can be explored but are single user Interest to the computing community Jasper fills a niche which the projects above do not As well as supporting more platforms such as Linux and Unix Jasper allows the reliable use of Unicode in conversations Another item of possible interest to the computing community is the Goo algorithm The Goo algorithm generates the landscape tiles used in the cre ation of the vast continuous landscape seen in the environment This algorithm runs quickly and creates natural looking features Depending on the level of recursion the output detail can be tuned to the desired amount This algorithm is of my own design 1 5 General statement of the problem The project must be able to support multiple users in the same online envi ronment It must run on more than one system architecture and must support Unicode characters to allow conversation in many languages The secondary requirements for this project are the ability of the user to modify the world to allow the project to run through a web browser and to improve the realism of the world with graphical effects Jasper was created to allow people on many operating systems to use the same 3D environment The aim of this project is entert
9. 64 2 64874 0 0780487 0 736369 lt Many lines removed gt 847 verticies vt 2 92053 2 6726 vt 3 2 6726 vt 2 92053 2 91641 lt Many lines removed gt 703 texture verticies usemtl MAT_ACDEAC f 834 1 840 2 833 3 f 832 4 833 3 839 5 f 833 3 840 2 839 5 lt Many lines removed gt 1641 faces lt lt 400 3 8 4 MTL Files OBJ files may specify a MTL file which is used to store materials values and texture filenames associated with the object A MTL file has the following form newmtl MAT_AAE6B4 Ka 0 117647 0 117647 0 117647 Kd 0 752941 0 752941 0 752941 Ks 0 752941 0 752941 0 752941 illum 1 91371e 305 Ns 8 newmtl MAT_ACDEAC Ka 0 0823529 0 0823529 0 0823529 Kd 0 823529 0 823529 0 823529 Ks 0 0823529 0 0823529 0 0823529 illum 1 91371e 305 Ns 8 map_Kd brick png Ka Kd and Ks specify the ambient diffuse and specular material for that object map_ Kd allows a texture file to be specified 17 3 8 5 TGA PNG TGA and PNG are open image formats Both are reasonably complex formats All PNG and TGA processing is performed by the OpenGL for Java libraries so it is not a requirement of this project to understand and re document the image formats Please see Bibliography for links to specification information 3 9 Use of Tools Libraries and Existing code 3 9 1 Java Profiler A Java profiler was used to examine the running of the applet and enabled the detection of bottle necks and inefficiencies in the s
10. Multi Language 22 4 4 4 Object buttons testing o a 22 445 User interface 22204 23 4 5 User Acceptance Testing o o e 23 4 6 User Interface Feedback 0 24 4 7 Problems found during testing o 24 5 Summary Costings and Critique 25 5 1 Source code length o o e e 25 5 2 Extent to which the aims of the project been fulfilled 25 5 3 Problems and difficulties 26 5 4 Main accomplishments to date o o 27 5 5 Main conclusions and findings Of project 28 5 5 1 User interest in virtual environments 28 5 5 2 How I would modify my methods if doing this project again 28 5 6 Further work a s setin Yia dl DA E a 28 6 Bibliography 29 1 Introduction and Specification 1 1 Key terms Throughout this document a few unfamiliar terms have been mentioned To clear up possible confusion the terms are defined here 1 2 1 3 Jasper Refers to the implementation of the client and server used as the online name for this project UniServer The server part of Jasper UniApplet The client part of Jasper Can be run as an web based applet or standalone if required Instance An individual item in the world each has a unique identifier Each instance is associated with a file to define its 3D shape Many in stances can have the same file
11. Multi Platform Multi User OpenGL Environment December 9 2006 The University Of Reading Department of Computer Science School of Systems Engineering 3 CS 7N Computer Science Project Final Project Report Multi Platform Multi User OpenGL Environment Supervisor Dr James A D W Anderson Second Reader Dr Rachel McCrindle Author Jonathan Waller Abstract The aim of this project was to create a multi platform multi user 3D virtual environment An environment that can be personalised explored and used for conversations in many languages The project uses OpenGL to create a graphically interesting world Light colour and intensity changes throughout the day stars become vis ible at night The landscape is seemingly infinite in size and can hold many millions of objects The project has designed to be multi platform and fully support the Unicode character set The main drive behind this project was the desire to remove boundaries from users allowing all to enjoy a 3D virtual environment By fully sup porting Unicode conversations can contain a much wider range of charac ters thus enabling native communication in practically all of the world s languages Furthermore by designing the software to be multi platform users of non Windows operating systems gain access to 3D interaction not previously available Many creative people yearn to demonstrate their artistic talents so personalisation was a key feature of this projec
12. ainment and communi cation To the author s knowledge there are no multi platform applications of this type that support Unicode characters Jasper was created to fill this gap A common problem is that applications have been customised for one char acter set and therefore will incorrectly render text in another character set This is the case with software such as ICQ Lite Chinese Simplified which due to encoding methods makes it impossible to show characters outside of Chinese simplified encoding or to mix two non roman character sets such as Arabic and Korean This is an essential feature for environments where many languages may be used 2 Analysis and Design 2 1 Why Java was chosen One of the key reasons was that programs written in Java can easy run on multiple physical platforms through a virtual machine Another reason was that Java can be used to create applets which run through a web page Other languages that can be used to create multi platform applications would have to be re compiled for the new architecture The programs created in this way would have to be downloaded and not be web based which was one of the secondary requirements of this project NET would not need to recompiled as it has a similar structure to Java s byte code and could be run on many platforms due to the open source NET implementation Mono However connecting NET to native OpenGL libraries would limit it to one platform only Un
13. ake an item transport you to a new area read a signpost or load the web page of the landowner 28 6 To add to the realism of the world better atmospheric effects will be added These will include items such as snow mist fog and reflection effects Allow the user to change their avatar this could be based on wealth to give users an incentive to trade Users may enjoy the opportunity to become an Alien or a Velociraptor The author plans to create a VRML converter as this is very commonly used format and would greatly improve the scope of the program VRML supports texturing materials animation prototyping text and a few other features The ability not to walk through apparently solid objects would add to the realism of the scene Collision detection and object obstruction will be implemented There are a variety of different general purpose collision detection algorithms that exist where the most accurate are quite com putationally expensive The author has devised an algorithm that takes advantage of knowledge about this game and creates a collection of bound ing boxes around elements of each object the advantage of this algorithm is that is can be run quickly and is not as crude as simply bounding the object in X Y and Z planes Bibliography VRML97 Specification ISO IEC 14772 1 1997 e Complete VRML Specification e http www web3d org Specifications VRML97 The Annotated VRML97 Reference Manual Virtual Worlds
14. ar were made larger as to be clearer to the user The radar was modified to remove the grey relief map use more contrasting colours and the points were made larger A command was added so that user could choose the size of the radar points 5 Summary Costings and Critique 5 1 Source code length At the start of this project the size of the final program was estimated to be 6500 lines of code spread throughout all the programs created The final program had the following lines of code e Applet 3711 e Server 682 e Total 4393 The applet is significantly larger in size than the server as all landscape genera tion environment rendering and model parsing is performed by the applet The server manages object locations and forwards on chat messages to the clients This preference for performing processing on the client is so that the server is under a much lighter load when a large number of users are in the world One of the main reasons for this discrepancy in sizes was the author s in experience in larger programs of this type OpenGL had been used in small programs of 200 to 300 lines but it was not known how this would map to more graphically demanding projects such as this one Also a few features that were envisaged at the outset were not chosen for inclusion into the final pro gram These included complex features such as collision detection and a large collection of 3d model file parsers to allow many different types of mo
15. as Architectural Space An exploration By Veronica e A comprehensive VRML description useful as quick reference e http www web3d org resources vrml_ref_manual Book html Zidarich e An essay on 3D online worlds community building and virtual design e www foundation langlois org e activites zidarich zidarich pdf Active Worlds e Large online community Features 3D worlds which users can participate in and add to e http www activeworlds com 29 VRML Worlds Gallery e Similar to VRML Homesteads a collection of VRML worlds that can be explored e http www avatara com vrml Kerin Spaink e Fascinating Essay on Net Art and Virtual Homesteads e http www spaink net english ArsPrix97 html BioCoRE Setting up your browser to work with Swing e 3rd party Swing implementation used to allow Swing components on In ternet Explorer s Java VM e http www ks uiuc edu Research biocore swing _setup shtml Extensible Java Profiler e A profiler for Java Created as a plugin for the Eclipse IDE e http ejp sourceforge net DAAP The first world of virtual sculpture on line e A 3D virtual environment where undergraduate artists display their project work e http www cerhas uc edu dwoodham daap2 htm PNG Portable Network Graphics Specification e Specification of PNG image files e http www w3 org TR REC png multi html TGA TARGA Specification e Specification of TGA image files e http astron
16. ava interface which is used to render the environ ment TCBG s Swing Jar TCBG 4 have created a swing jar file for use with their BioCoRE application This 4The Theoretical and Computational Biophysics Group at the University of Illinois at Urbana Champaign 18 jar file was used to allow the use of Swing components in the applet without requiring an updated version of the VM This is very similar to the one from Sun with the advantage that the TCBG jar file could be linked to as a class archive from the applet and did not need to be copied to the computer s local drive 4 Testing and Quality Testing was performed in three stages e Module testing This project was developed using the evolutionary pro totyping method After each evolution the new features and classes were tested thoroughly The functions and procedures of the classes were inves tigated to try to find errors This was performed by creating a set of test harnesses for each of the classes Some programs external to the project were used to test the operation of sockets in networking classes e Speed and Load testing Although the project does not need to handle a extreme number of users it was interesting to discover the number of users that could connect before the system became unusable e User testing An important part of any testing is how the end user inter acts with the software and any changes they wish made to the software At the end of development
17. d extreme and unusual but valid data for example the system time was never negative and protocol strings were correctly formatted However for User Interface func tions the testing was much broader and included inputs that might be seen as malicious Although this is good method for ensuring that the program is bug free it does not cover some important issues such as how the server will cope under high load due to many users Module testing was an iterative process as some classes presented errors when given unusual data and so were fixed and retested 4 2 Speed It is was important that the applet did not run too slowly with many items in view Although there was no user noticeable slow down the author re implemented the rendering routine to an array based system increase the frame refresh rate The applet has been tested on a 400MHz machine with 20 objects on the screen and ran smoothly Highly detailed objects over 500KB will not be downloaded 4 3 Load testing Setting up the server and simultaneously connecting it from 12 computers did not cause any noticeable slowdown and the server was not under high load Running many applets on the same computer did cause the applets to become slow but the applets perform much more processing than the server and it not expected that more than one applet will be simultaneously run on the same computer The preference for performing processing on the client is so that the server load is
18. dels to be imported 5 2 Extent to which the aims of the project been fulfilled Primary objectives of the project e Multi user 3D environment This aim has been fulfilled It is possible to connect multiple clients to the same server position and rotation of one user around the scene is reflected in other client s displays by the movement of an avatar Users can request a nickname to be used within the environment and then may send text to each other 25 e Allow the client program to be multi platform This aim has been fulfilled The client is written in Java and so may run on any compatible virtual machine The use of the GL4Java native classes restricts the platforms marginally but GL4Java will run on Win32 Macintosh Linux Unix and Solaris systems The disadvantage of not not being to able to run the client on less widely used operating systems such as BeOS and HP UX is outweighed by the convenience and speed of OpenGL e Enable communication with the full Unicode character set This aim has been fulfilled As mentioned before when connected to the server users may send text to each other This text may use any Unicode characters Unicode text input has been tested on Win32 with Microsoft s Japanese Input System MS IME2000 This makes it possible to send correct Japanese text containing Hiragana Katakana or Kanji from one user to another Other languages that require Unicode such as Korean Mandarin and Cantone
19. e client Currently the default Java fonts are not Unicode compliant Swing is needed to use a Unicode font Internet Explorer uses version 1 1 of the Java VM and thus does not have Swing This was solved by using a 8rd party swing implementation BioCOrE which was linked to by the applet Java Security features Java s security model caused a variety of problems for the development of this application 5 4 Applets cannot connect to a server when they load This was worked around by creating a Thread that dealt with all commands sent to and from the server Strangely this did not have the same restriction even when the thread was created when the applet was started An applet can only connect to the server of the computer that it was downloaded from This means that if the user wishes to download a 3D model file from an arbitrary place on the web they cannot This restriction was solved by building a simple proxy into the server which allow the client to request files through the server from anywhere on the Internet Main accomplishments to date Creating a modular framework so that different converter classes can be easily added so the functionality of the applet can be extended Created a variety of converters to import all kinds of file types into the environment Creating a download queueing system that only downloads one file at a time but can understand dependencies required needed for the creation of there objects and can
20. ghtialo ro a Aa 3 4 Landscape features o e 3 4 1 Infinite Landscape Generation 3 4 2 Landscape Tile Blending 3 4 3 Goo algorithm lt sst ip ede ee Bde MA a Ee 3 4 4 Dynamic land colour 2 3 5 File Converters o coss oom 000 eee 3 5 1 ASC PC and OBJ Model import 3 5 2 Extensible Converter Architecture 3 6 Specification of programs a aooo e e 3 6 1 UniAppl bu cursos aaa a E 20 36 2 WniS rver tulo do ia ats de ee a AR A 3 6 Other Information faz td e o 3 7 1 Technical difficulties experienced 3 7 2 Data structures employed 2 3 8 Data input and Formats o e BBall A O ee te iad ee BSE aa ISLAS Ones mtd a oi A a ai 3830 OBI S025 Gg Page tet e 2D Aa ee Bi eed a 3 84 MTE Files ascos aca riada 8 55 38D TGA PNG do fee a bd pede BARB RRS ED 3 9 Use of Tools Libraries and Existing code 18 3 9 1 Java Profiler a E A E e e 18 3 9 2 Java Integrated Development Environments IDEs 18 3 9 3 Reimplementation of functions 18 3 9 4 Third party Libraries o 18 4 Testing and Quality 19 4 1 Module testi ci aye e pa a 19 42 Speeds a eaea A A A A 20 43 Load testing daneas A REM A E a 20 dd User Testing ai si A e e e e a AaS 20 4 4 1 Nickname selection 20 AR Mri USC mari de a eee ee eee a DE o 21 4 43 Multi Platform
21. hange will be more gradual 3 3 3 Starfield at night The star filed is random but based on a fixed seed so that all clients will get the same star field The stars are clearest at midnight server time but fade See figure 6 in pictorial appendix for a data flow diagram of the 3D object download and conversion process 2This relationship is demonstrated in Figure 5 of the pictorial appendix 11 into the sky gradient gradually becoming indistinguishable at 6am and 6pm and throughout the daytime 6am to 6pm Stars closer to the horizon blend to the horizon colour 3 4 Landscape features 3 4 1 Infinite Landscape Generation Tiles are generated when they are within 40 meters of the user As can be seen from Figure 1 in the Pictorial Appendix as a user walks into an area requiring a new tile the new tile will be generated blended with existing tiles and rendered Tiles are generated by the client as required Each tile is generated by a seed that is dependent on its global coordinates This means that when a tile at a particular location is generated concurrently on two clients the shape of the landscape tiles will be the same As the seed can be calculated by the client as it knows the avatar s location no landscape data has to be sent to or from the server for consistent landscapes across all clients The Goo algorithm creates independent tiles To ensure that the tiles knit together at their edges a blending tech
22. l form which can be read by the application e ASC files are 3D Studio Max ASCII files The format stores verticies face and face colour information RGBA e JOF Point cloud PC files are a simple format to store the verticies of an object No material or face information is stored In the environment PC models have been used to create explosion effects and a transparent looking tunnel e OBJ files are Alias Wavefront Object files The files store faces and verti cies as well as material information diffuse specular ambient emission Materials can be assigned textures This model format is useful when you wish to have more control over the material of your object causing it to glow or become more shiny for example 3 5 2 Extensible Converter Architecture All converter classes are inherited from the abstract Converter class This pro vides arrays to store model image or material details in a generic form It also contains the abstract function doConversion New converter types that have been inherited from the Converter class must implement doConversion This takes the raw data from the file and converts it into a generic model image or material form that can be read in a consistent way for all file types This allows programmers to create a converter any kind of image 3D model or other file type provided they abide by the simple interface A prerequisites system is in place to ensure that all objects are processed in
23. like OpenGL for Java which is a multi platform wrapper 2 2 Why OpenGL was chosen A graphical framework was needed as the author did not want to render the scene in software as this would be very slow The two most widely used graph ical frameworks are DirectX and OpenGL OpenGL is cross platform however DirectX only runs on Windows systems Finding the OpenGL for Java classes finalised the author s decision to use OpenGL 2 3 Applet Classes CmdThread Manages thread that connects to the server Deals with user commands and commands sent from the server Periodically informs the server of the new avatar position Forwards messages to the InstanceMngr Server and LogBox Converter The abstract base class for all the file converters Contains helper functions for converting between types generating normals and copying arrays Contains model arrays that can be accessed in a uniform way independent of file type ConverterASC Allows 3D Studio Max ASCII model files to be converted to a generic model format ConverterMTL Allows Alias Wavefront material files to be converted to a generic material format ConverterOBJ Allows Alias Wavefront Object model files to be converted to a generic model format ConverterPC Allows JOF Point cloud model files to be converted to a generic model format ConverterPNG Allows Portable Network Graphic image files to be con verted to a generic texture format ConverterTGA Allows Truevision Ta
24. me They are sent this message Followed by the new nickname Your nickname is now Currently multiple users may choose the same nickname which could cause confusion A dummy function is used to check for duplicates but could be easily extended This is shown below boolean nickInUse String nick 4 return false Tf this function returns TRUE then an 0 is added to the end of the nickname In the event of a collision this number is incremented until a unused nickname is found 4 4 2 Multi user Multiple users can exist in the same environment at the same time position and rotation of each user in the scene is reflected in other client s displays by the movement of an avatar In the current version of the program other users are shown as rabbits mirroring their user s location Users can type messages to each other Users are identified by a nickname which they choose when they first load the applet Objects that have been placed and saved in the environment by a user can be seen by all other users 21 4 4 3 Multi Platform Multi Language The program was primarily developed and tested on the Windows operating system with Internet Explorer as this is the most common combination of software that the applet will be used with The applet has also been tested with Linux The client is written in Java and so may run on any compatible virtual ma chine The use of the GL4Java native classes restricts the platform
25. n instance change within their field of view The server will broadcast all chat messages sent from a user As a separate service the server operates a proxy for files By sending a URL to the open port the file will be sent back back the server or an error if the file cannot be found 3 7 Other Information 3 7 1 Technical difficulties experienced The default version of the VM which comes with Internet explorer does not support Swing which was used to draw the components on the user interface This was solved by using a Third party Swing Jar file from BioCoRE 3 7 2 Data structures employed Vectors are used to store lists of objects This technique is used in FileMngr to hold a collection of FileObj objects containing information about files that have been downloaded Vectors are also used on the server and the client to store all of the world instances 3D models are converted to a generic form and stored within the arrays of a FileObj 15 3 8 Data input and Formats 3 8 1 PC JOF Point cloud files are a simple format to specify the points of an object It was initially used as a simple converter class tester but many users have found it useful for explosion effects The file format is as follows 256 X 1 027030 Y 0 123684 Z 0 634111 X 0 945148 Y 0 535328 Z 0 634111 X 0 711971 Y 0 884303 Z 0 634111 X 0 362996 Y 1 117480 Z 0 634111 The first line states how many lines to read one line per point And then each subseque
26. nique has been implemented 3 4 2 Landscape Tile Blending To create a smooth landscape from the generated tiles the tiles have to be blended together There are two 3x3 grids making 18 landscape tiles that are generated The second plane of tiles is offset by half a tile width in the x and z axis so that the middle of the top 9 tiles overlay the top left corners of the lower 9 tiles To generate the height at a particular point on the landscape the two heights at that point on the landscape are added together with a bias on which is closer to the centre of a tile To calculate a point that falls halfway between the middle of the tiles half of the height will be derived from one tile and half from another The advantage of this is when the sampling point approaches the edge of an overlapping tile the influence of that tile becomes zero and the middle of the other tile is used so that the areas where the tiles would not bind together are of no influence and the landscape is smooth To demonstrate this please regard Figure 4 in the pictorial appendix The X is closer to the centre of tile A than tile B The calculated height at point X will be biased toward the height at X on tile A with B having a lesser influence As X approaches the edge of tile B the height of B has less and less of an influence on the output height The following equation describes this relationship Height H A Distance to centre of B H B Distance to centre of
27. nt line states the X Y and Z coordinate of a point The size the point is drawn on screen is fixed at 5 pixels 3 8 2 ASC The 3D Studio Max ASCII file is a human readable format which stores vertex face and colour information as well as smoothing The format is shown below Named object Sphere Tri mesh Vertices 467 Faces 938 Vertex list Vertex 0 X 0 0633293 Y 0 123308 Z 3 78605 Vertex 1 X 0 0633293 Y 0 123308 Z 0 0 lt Many lines removed gt Vertex 466 X 3 47911 Y 1 46055 Z 2 17891 Face list Face 0 A 2 B 3 C 0 AB 1 BC 1 CA 1 Material ri0g255b3a0 Smoothing 1 Face 1 A 3 B 4 C 0 AB 1 BC 1 CA 1 Material ri0g255b3a0 Smoothing 1 Each face is assigned a colour RGBA which allow the surface to be transparent Many submodels may exist in one file The Smoothing field is ignored All objects in the environment are drawn with smoothed colours but non smoothed normals 3 8 3 OBJ Below the OBJ format is described 16 Comments are signified by a line starting with a hash symbol Ifan MTL file is associated with the OBJ file then this will be specified with mtllib Lines starting with v vt and f signify verticies texture verticies and faces respectively usemtl refers to a material change Material information is found in the MTL file A sample OBJ file is shown below Wavefront OBJ file mtllib 7g_hut mtl object MBconv MBconv 2 64874 0 0815319 0 732645 2 64874 0 0780487 0 7259
28. omy swin edu au pbourke dataformats tga The Programmer s File Format Collection e Collection of specifications for many file formats e http www wotsit org 30 Mono Project e Open Source implementation of NET Development Framework e http www go mono com 31
29. ort line wrapping and Unicode fonts ObjConvertThread Manages a queue of objects to be converted Selects and runs an appropriate converter to convert a file into its generic form ObjDownloadThread Manages a queue of objects to be downloaded Down loads requested files Limits files to under 500KB OpenGLCanvas Stores the user s position and rotation in the world Man ages time based lighting Generates and draws the radar and sky dome Re ceives keyboard input for user movement Calls rendering routines in the In stance objects and Landscape object ProtocolStringHelper De constructs and constructs protocol compliant strings Contains functions to return part of a protocol string such as the command or the sender Allows easy construction of protocol compliant strings that can be sent to the server TextEnterBox Inherited from JTextField Single line text box extended to support Unicode fonts When Enter is pressed the input is sent and the text box cleared UniApplet Main applet class Generates the user interface and sends all user input to GLCanvas Allows the applet to run within a web page or as a standalone Java application 2 4 Server Classes ProtocolStringHelper De constructs and constructs protocol compliant strings Contains functions to return part of a protocol string such as the command or the sender Allows easy construction of protocol compliant strings that can be sent to the clients InstanceSObj Data only
30. ource code A function to calculate the height of each point on the landscape tile was being called many thousands of times a second To fix this the landscape heights were precalculated and stored in an array The internal representation of 3D models were stored as a string containing a list of commands to be carried out to create the object This was very extensible but led to many thousands of string comparisons every second This was remedied by storing the model format in arrays to hold verticies normals materials texture indexes and a final faces array that points to 3 indexes in the vertex normal and material arrays 3 9 2 Java Integrated Development Environments IDEs Java was used as the programming language for the server and the client The IDE used was initially Microsoft Visual J 6 0 but was then switched to IBM s Eclipse Platform as it allowed simultaneous debugging of the server and client plugins such as a profiler and had a more understandable multi thread debugging interface 3 9 3 Reimplementation of functions Some functions such as String replaceAll were not supported on the virtual machine installed with Internet Explorer These functions were recreated so a new version of the VM would not be required 3 9 4 Third party Libraries OpenGL for Java OpenGL for Java is a third party library created by Jau soft This library a creates a wrapping of the underlying system s OpenGL capabilities and presents a J
31. owing their creativ ity and will create special structures to display to others This interest can be seen in the construction of DAAP The first world of virtual sculpture on line where undergraduate 3D artists display their project work in a virtual environment Improve realism of world By using a variety of effects the virtual world can become more realistic Example techniques could include lighting and terrain effects Lighting effects and sky colour can be based on the client s local time Web based It is important to allow the project to be web based as some users cannot install software on the computer they are using To this end it has been decided to create a Java applet than can run through a web browser External Review Similar projects The projects show below demonstrate some of the functionality in Jasper such as a 3D environment or Unicode support 1 4 2 MSN Messenger MSN Messenger is an popular instant messaging tool which allows users to chat to one another No 3D environment is supported MSN Messenger supports Unicode characters but only works on Windows and Mac It also has to be installed with Administrator privileges Activeworlds Activeworlds is a client that allows access to a collection of 3D environ ments Facilities exist to import objects into these environments and to talk with others The client only runs on Windows systems Unicode support in Activeworlds was only added after Jasper
32. radar point size and to import model files not in the quick object list are accessed though commands in the chat window There are three buttons that allow the user to create select and save objects into the scene The user can walk around the scene to choose the desired position and rotation of the new object This procedure has strong visual feedback and users had no difficulty creating complex scenes with multiple objects After selecting a wrong object to place in the scene one user quickly remedied their actions without help by clicking again on the object selection button and continued building his scene Thus showing the intuitive nature of the interface The applet was tested by a variety of users chosen for their native language and varying familiarity with computer software The native language of partic ipants included Korean Japanese and English The ages ranged from a year 6 primary school student to adult users Inputting text in non roman characters Japanese for example is possible by using the standard input methods IME for Windows kinput2 for Linux No new techniques need to be learned 4 7 Problems found during testing The radar was brought up as topic of concern The original design of the radar was a grey level relief of the surrounding landscape showing the peaks and valleys in the local area On user commented that is was sometimes difficult to see clearly 24 An other user suggested that the points on the rad
33. reorganise the queue accordingly Creating a landscape generation algorithm using a seed based system In tegrating this with the gradient colouration and blending algorithms Allowed the project to support Unicode on many platforms Ability to send and receive chat messages written in any language Allowing many users to inhabit the same scene Users can see and talk to one another Creating a variety of environment effects to improve the realism of the scene Infinite landscape generation Clients will generate the same landscape without needing to send landscape data from the server Allowing the user to change their environment with the import of 3D models 27 5 5 Main conclusions and findings of project 5 5 1 User interest in virtual environments Having placed the applet on the web I found the user uptake and involvement to be much higher than I expected It seems that multiple user environments are very popular and the 3D graphics or Unicode support has helped to draw users to the project 5 5 2 How I would modify my methods if doing this project again I would have added land and item ownership at an early stage To tack on a land or item ownership system at this stage of development would require a lot of programming 1 would have added object and land ownership from the early stages so that this would be integrated into the whole and the code would remain neat I would have created a wide selection of conver
34. rga image files to be converted to a generic texture format FileObj Contains arrays holding information about a file in a generic model material or image format Contains a render procedure to render the file to the OpenGL environment FileMngr Manages all the FileObj objects Requests Download and Conver sion of required files Acts as a cache for downloaded files of all types Returns a FileObj when given a URL address GlobalDate Keeps track of server time used when creating the sky and light ing colours InstanceObj Contains information about the location and rotation of an object its Unique Identifier and the URL of the file it is rendered with Contains a render procedure which calls the render procedure of its associated FileObj InstanceMngr Manages all InstanceObj objects Allows addition and dele tion of instances Responsible for deleting instances of objects that are outside the client s view distance JTGATextureLoader Inherited from GL4Java s TGATextureLoader Al lows the loading of textures from an InputStream not a URL This is required as all file transfers are proxied though the server LandscapeMngr Responsible for all processing related to the landscape This includes creating required landscape tiles as the user walks around the world blending tiles together and applying colour to the landscape based on the landscape features LogBox Inherited from JText Area A multi line text area extended to supp
35. s marginally but GL4Java will run on Win32 Macintosh Linux Unix and Solaris systems The disadvantage of not not being to able to run the client on less widely used operating systems such as BeOS and HP UX is outweighed by the convenience and speed of OpenGL The server runs identically on Windows and Linux systems as would be expected on any system with a Java virtual machine The applet was tested in a selection of popular browsers Mozilla Firebird Firefox Internet Explorer Opera and Netscape As mentioned before when connected to the server users may send text to each other This text may use any Unicode characters Unicode text input has been tested on Win32 with Microsoft s Japanese Input Method Editor MS IME2000 This makes it possible to send Japanese text containing Hiragana Katakana or Kanji from one user to another Other languages that require Unicode such as Korean Hindi or Arabic can be input in the standard operating system way Either with a different keyboard layout or with an IME Linux Unicode input can be achieved through kinput2 As shown above Unicode nicknames are also supported Windows will correctly display Unicode text if a compatible font is available Linux correctly displays Unicode text provided that the Dialog font for Java is a Unicode font this is easy to set and should be enabled as default If no Unicode fonts exist on a system then Unicode text cannot be displayed However Unicode fonts ha
36. se will also be input in a similar way Unicode nicknames are also supported Secondary objectives of the project e User customisation This aim has been fulfilled Users are able to add models to the world and create scenes with standard objects or objects of their own design Models can be arbitrarily placed anywhere in the landscape and once saved are shown to all other users A system is in place to ensure that clients are only sent information about instances that are relevant to them and so the server can hold many millions of instances when the client only needs to render a very small number in a particular area e Improve realism of world This aim has been fulfilled Fixed sky lighting has been added to the world and object surfaces are lit correctly by using face normals All face colours in RGBA form have been converted to materials e Web based This aim has been fulfilled The client has been designed to run as a web based applet or as a standalone application The problems caused by Internet Explorer s VM have been solved and the applet has been tested in many browsers 5 3 Problems and difficulties Allowing Unicode support within Internet Explorer without requiring an upgrade of the standard VM Java has two main windowing methods AWT and Swing Swing was built to replace AWT 26 As far the as the author can see it is impossible use a Unicode font in AWT without editing files on each computer that uses th
37. t Allowing users to explore the world and come upon undiscovered areas that have been adapted by another user allows a much stronger connection to the medium than instant messaging may have The intention was to create an engaging and enjoyable experience for all users The aims of this project have been realised The environment that can be personalised and explored Unicode chat has been implemented and tested in a variety of languages Contents 1 Introduction and Specification ED AG AAA eb ee ee i oe a ee he BD 1 2 Primary objectives of the project 2 1 3 Secondary objectives of the project 2 1 4 External Review 2 02 2 000202 eee eee LAT Similar projects seins a ee PA eee Sees 1 4 2 Interest to the computing community 1 5 General statement of the problem Analysis and Design 2 1 Why Java was chosen 2 02 0 000505 2 2 Why OpenGL was Chosen o o 2 3 Applet Glases 2 2 4 lt P wok RL et RR eS 2 4 Server Classes so cor ao ooe e ea 020002 eee eee Development and implementation 3 1 Development method o e e 3 2 Command Infrastructure a aooaa a 3 2 1 Server Operation a aoao a 3 2 2 Client Operation a aooo 3 3 Graphical effects s sa noo eoi a o me e a a a a a E i 3 3 1 Time of Day Lighting 3 3 2 Dynamic sky colour gradient 3 3 3 Starfield atini
38. t Contains the sendObjectsIn SightOf procedure which informs the client of all instances that are close to the user UniServer Starts serverCmd and serverObj 3 Development and implementation 3 1 Development method The project was developed using the evolutionary prototyping model This involved creating a working prototype as soon as possible and then improving it in steps each cycle having a running application to test The tree like structure of dependencies in the client restricted this slightly but gave a much stronger structure to build the rest of the application around 3 2 Command Infrastructure The project consists of two parts a server UniServer and a client UniApplet Both are written in Java The server listens on two ports for incoming connec tions The client is a Java applet loaded in a web page when the page is loaded the client connects to the server Many clients can be connected to the server at the same time so that many users can co habit the same 3D environment There is well defined extensible human readable protocol that the clients and server must adhere to Version problems are very unlikely due to the client being a Java applet and being re downloaded each time it is run 3 2 1 Server Operation The server listens on two ports for incoming connections one data port and one command port Data Port Due to security restrictions for applets applets can only open connections to
39. ters for many different types so that users could import a much wider range of objects However overall the author is very pleased with the development of the application and was helped by the class structure designed before the imple mentation was started as this helped to bind the project together 5 6 Further work This project is ongoing and due to the surge in public interest the author has decided to continue the project Possible additions to the project are as follows Not all of them may be implemented but suggest what could be done e Create a much more developed item infrastructure Allow users to have an inventory in which items can be stored e Allow goods to be created bought and sold Add wealth in the form of a currency or purely by a barter system e Users may be allowed to modify the terrain in certain areas to further customise the world Users could add a mountain range close to their house or create a valley to enhance the appearance of their area e Create an ownership system of land A problem with the current system is that users can place inappropriate objects in an area that another user has spent a lot of time customising Allowing a particular user to own a portion of land and only have rights to put items in that area would protect it from this kind of vandalism e Allow signposts to inform the users of information Include click able items with context sensitive actions clicking could t
40. that the avatar or another object under client control has moved 3 2 2 Client Operation All of the rendering is performed in OpenGL in the client program This is achieved by using the OpenGL for Java classes 3D model rendering When the client first connects it receives a list of near objects from the server in obj line form shown above This line updates or adds to the contents of the instance list depending on the UID If the associated 3D model file is not in the File Manager Cache It is then downloaded and converted All objects within the instance list are then rendered to the screen Objects that move far away from the avatar are removed from the instance list This instance list is then rendered to the screen using the associated position and rotation data 3 3 Graphical effects 3 3 1 Time of Day Lighting When the client connects to the server it is sent the server s local time This ensures that all clients have an identical time which is used when creating the sky and lighting colours 3 3 2 Dynamic sky colour gradient The midnight sky gradient consists of a deep blue at the horizon fading to black directly above the viewer The noon sky gradient consists of a light blue at the horizon fading to a mid blue The ratio of day to night colours is not a linear relationship but follows a cosine wave meaning that the greatest changes in sky colour will occur around dawn and dusk around noon and midnight the c
41. the correct order For example OBJ files may store material information in a separate file linked to from within the OBJ file The 3D model cannot 14 be converted into an array representation until the materials are known so the model processing is halted the material file is downloaded and processed and then the model file can be processed 3 6 Specification of programs There are two programs that make up Jasper UniApplet and UniServer 3 6 1 UniApplet UniApplet is the client which runs either as an applet or as a standalone ap plication It connects to the server and downloads Instances close to it in the world Any associated files that it does not have in cache are downloaded and converted into a generic form for their type model image or material file The interface then renders all of the Instances in the scene by referring to their associated model files The user can walk around the environment with new landscape tiles being generated if they enter a new area The user s location is periodically updated so the server can inform all the other clients of this user s new location Users can select and add Instances to the environment with an associated object These can be saved to the server for all users to see 3 6 2 UniServer UniServer is the server part of Jasper and runs on a computer permanently connected to the Internet The server keeps track of all instances in the world and informs users if there is a
42. the environment 4 4 5 User interface It was important that the interface of the application was easy to use for many types of users Careful consideration was taken when creating the user interface to ensure that it was intuitive and did not rely too heavily on English for actions to be carried out Although the text of the buttons is in English the text is simple and the user will work from left to right when adding a world object The users withe English not a first language seemed to use the interface without difficulty Also the user manual can also be translated into other languages 4 5 User Acceptance Testing To ensure quality of the final product the applet was made accessible though the authors website and some users were asked for their opinions on it Concerns that were brought up were as follows The landscape seems to change colour if you turn quickly This was because the land position was updated before the sun was moved and so the sun took one frame to catch up to the correct position The rendering order was changed and this problem was solved There are only trees close to the start point To make the environment more interesting the initial world is given 40 pine trees two houses and a signpost in fixed locations More trees can be added by users There s nothing on the signpost The signposts that can be added to the scene are only used for decoration Though using them to give information to the user seems
43. the web server that they were downloaded from This means that an applet cannot directly download a file if it is not stored on the same web server The data port solves this problem by creating a simple proxy so that the client applet can request a file from UniServer and UniServer will download the file and send the data to the applet that requested it This connection is used to download all the files that the applet needs 3D models and images for example Command Port A central server stores all the information about the world including the locations of objects within that world When a client connects to the server information about the closest objects to that player is sent to the client When the applet first loads it will connect to the command port on UniS erver UniServer will then send a list of all the objects close to the player s location object information is in the form obj UID x y z rxz ry rz URL Each instance of a 3D model has a UID unique identifier this allows the client and server to keep track of all the instances of each object The UID is guaranteed to be globally unique 10 Some objects such as the sky dome are always the same relative distance from the player These objects are sent in the same way but use wobj as a specifier Should an object move in the scene an obj line is created and sent to all connected clients who are close to that object The client sends obj lines to the server to inform it
44. ve been shipped with Windows since Windows 98 and also come with recent versions of Office Other Unicode fonts such as Bitstream Cyberbit are also available and can be used on Linux and Windows Arial Unicode MS and MS Gothic are both fonts created by Microsoft which support different planes of Unicode characters MS Gothic is a fixed width font and is used primarily because it is simpler to do line wrapping 4 4 4 Object buttons testing Three buttons control the addition of objects into the environment Create Object Change Object and Save Object e Create Object Makes a signpost a fixed distance in front of the user This shows where the new object will be placed The object is drawn a fixed distance in front of the user and thus can be moved to the desired location 22 e Change Object Changes the object s model file To a tree or house for example e Save Object Saves the object to the server and attaches it to fixed place on the ground The standard order is to click the Create button choosing a new location clicking the Change button to choose a new object and then clicking save after making a final decision The buttons can be clicked in any order doing as one would expect Clicking save when there is no object on the screen does not change the environment You may walk around after choosing a new object or you may skip choosing an object and just save a signpost to
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