Programming Language Support for Collaborative Virtual Environments

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Programming Language Support for Collaborative
Virtual Environments

• Clint Jeffery
• University of Idaho
• jeffery_at_uidaho.edu

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Why study games?

• Fun!!
• Computer game industry is big
• Larger than the film industry
• Shortly to eclipse the music industry
• Games drive technological advances
• Games have many serious applications
• Simulation, film, education/training
• Both software problems (e.g. AI) and
  engineering problems (e.g. cost, time)

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Game Technologies

• Game development is a specialized form of
  software engineering
• Lots of graphics, Lots of art
• A/I, Physics
• Networking
• Usually a simulation of some kind
• How to engineer fun?
• How to reduce the cost of development?

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What is a Virtual Environment?My definition for
purposes of this talk

• 3D, video game-like
• Multi-user, collaborative environment
• Persistent virtual world
• I am interested in building them
• For both games and serious purposes

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WoW
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What do we knowabout WoWs internals?

• Rumored to cost 60M to develop initially
• Uses Lua as its interface customization extension
  scripting language
• ?
• I suppose we could try to hack it, but I am not
  willing to risk losing my level 58 undead
  warrior
• Could imitate their dev model, just need 60M and
  more expertise than Ive got.

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Challenges

• Given 0, how do I
• Create a 3D world that is cool enough
• make or buy ? (make sounds hard)
• Collect lots of textures
• Build a detailed 3d model of my world
• With enough stuff to do to be interesting
• Stuff that is education-relevant
• Implies edu domain-specific tools
• What you can buy wont have these

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Research Avenueswhere you see state of art
substitute WoW

• Difficult to advance state of art in
• graphics
• networking
• Moderately easy to advance state of art in
• if you can even get in the game...
• AI gameplay
• Educational uses
• Necessary to advance state of art in
• Cost of coding
• Cost of art, modeling, content creation

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Hypothesis

• If I build the right language and tools, the cost
  of developing custom MMOs will become tractable.
• So far graphics and networking
• Future AI, physics, 3D modeling, art

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What does Language Support Really Mean?

• Functions, operators, keywords, and/or Control
  Structures
• syntax! ouch! Justifiable bug avoidance, e.g.
  matrix stacks, named render sections
• Simplifying OpenGL and sockets
• Built-in smart behavior, but flexible
• Generalizing things like input handling (select()
  and non-blocking read())
• Deciding what to do in C, and what not

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Textures

• 2D image, to be drawn on a 3D surface
• Harder than I thought it would be
• Start with digital photos of everything
• each room needs 3-300 photos
• Tedious manual editing process!
• crop dimensions to power of 2
• remove irregularities
• scale them down to fit more in
• most textures need to be tileable
• may need GIMP or Photoshop

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Texture Example
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3D Model

• If CAD/blueprint data is available, use it if
  you can read/understand/convert it
• Otherwise, start from floor plans
• Give (x,z) coordinates add your ys
• Decide on a coordinate system
• Where is 0,0,0? Feet or meters?

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Modview
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Scripting Example (SecondLife)
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User-defined Content

• SecondLife lets users create the world
• We are going to let users create the quests
• Quests will be dual-peer rated for (fun,xp) where
  completers rate the fun, domain experts rate the
  xp.

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CVE

• CS educational virtual environment
• Initial funding from NSF ATE program
• Lives at cve.sourceforge.net
• Runs on X11 and on Windows
• (OpenGL so far it stinks on Vista)
• SIMPLE 3d worlds, needs more tools
• Collaborative IDE
• Under construction
• Departments so far UI and NMSU CS

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Static and Dynamic Model Data

• static properties of a door
• Door
• x 33
• y 0
• z 3.9
• height 2.3
• plane 3
• rooms SH 167, corridor 167
• dynamic state of a door
• link
• name link1
• openness 1.0
• delta 0
• direction 1

static properties of a room Room name SH 167 x
29.2 y 0 z 0.2 w 6 h 3.05 l 3.7 floor Rect
texture floor2.gif obstacles Box
window sill Rect coords 29.2,0,.22,29.2,1,
.22,
35.2,1,.22,35.2,0,.22
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Under Construction

• High-level object selection
• 3D model imports
• better avatars, more virtual objects
• NPCs and quests
• CS/library tutorial content
• a recruiting tool, will reach grades 4
• Collaborative debugger (pty API)
• Collaborative design (UML--) tool
• Augmented reality and virtuality

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S3D Files

• // version
• 103
• // nTextures,nTris,nVerts,nParts,nFrames,nLights,n
  Cameras
• 1,892,445,1,24,0,0
• // partList firstVert,numVerts,firstTri,numTris,"
  name"
• 0,445,0,892,"pCube1"
• // texture list name
• uvmap.tga
• // triList materialIndex,vertices(index, texX,
  texY)
• 0, 8,33.7125,75.1163, 42,32.1658,78.5249,
  9,31.0493,70.0337
• 0, 30,93.7656,9.30429, 5,96.9879,15.1088,
  2,94.4741,16.4074
• 0, 103,209.125,250.495, 106,211.483,238.497,
  85,212.028,244.752
• 0, 30,93.7656,9.30429, 39,97.957,10.0346,
  5,96.9879,15.1088

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New This Spring

• NASA MMO
• Planning stages K-12 edutainment recruiting
• Direct3D port
• maybe shaders, while we are at it
• Mac/Cocoa port
• duelling infinite loops

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I Need Help

• Want to build more of uidaho?
• Id love to work with you
• Want to help?
• projects for students and new friends
• standalone tools, or core system elements
• NPCs
• Both game and educational stuff to do
• Instructional activities (quests/skills),
  experience points and peer ratings system