Enriching Scholarship 2001

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Principles of 3D Modeling and CAVE
Programming Imaging Technology Lab Media Union
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The CAVE
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• A typical VR application is divided into
  components
• A program
• Describes all interactions, behavior, animations
• A geometric model
• All the geometry created with common tools, such
  as 3D Studio, AutoCAD
• Sound
• Sound files (access to sound servers)

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The Model
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• Programming
• There are different ways to program the CAVE
• Toolkits, such as CAVELib or VR Juggler
• Basic graphics packages, such as OpenGL or IrisGL
• Higher open packages, such as Inventor or
  Performer
• Higher commercial packages, such as WorldToolKit
  or eNai

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The System
Unix (Irix, Linux)
C
Performer
CAVELib
Additional in-house libs
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• Performer
• Designed for high-performance interactive
  graphics
• Very efficient, if there is more than one view in
  a scene
• Classes for multiprocessing
• Classes for scene manipulation
• Libs for C and C
• Generates calls for IrisGL and OpenGL

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• CAVELib
• Specifics of CAVE
• Displaying
• Interaction
• Tracking
• Networking

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Basic Program (outline.cpp) include
ltpfcave.hgtint main(int argc, char argv)
pfInit() pfCAVEConfig(argc, argv, NULL)
pfConfig() pfCAVEInitChannels() while
(!CAVEgetbutton(CAVE_ESCKEY)) pfSync()
pfCAVEPreFrame() pfFrame()
pfCAVEPostFrame() CAVEHalt()
pfExit() return 0
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Compiling CC -I/usr/local/CAVE/include -DOPENGL
name.c -o name \ -L/usr/local/CAVE/lib
-lpfcave_ogl -lpfdu -lpfutil \ -lpf -lGL -lXi
-lX11 -lm -lfpe -lC -limage
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.caverc Units inches Units feet Units
millimeters Units centimetersUnits meters
DisplayMode mono Simulator y Wall front
Wall front floor right leftWandSensorRotation 1
0 0 0WandSensorOffset 0 0 -9 inches
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Simulator Move wand with CONTROL mouse movement
or SHIFT mouse.Rotate wand with ALT mouse
roll wand with 'lt' / 'gt'.Move head with arrow
keys or SHIFT arrow keys.Rotate head with ALT
arrow keys.Reset tracking with 'P'. Mouse
buttons correspond to wand buttons.Joystick
operated with SPACEBAR mouse movement. 0 Wall
view (select wall with 'F'/'L'/'R'/'B'/'D')1
Perspective view2 Outside view (use numeric
keypad to rotate/zoom view)
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• Loading geometry
• Supports a wide range of formats, such as
• SGI Open Inventor (.iv)
• Wavefront OBJ (.obj)
• AutoCAD DXF (.dxf)
• AutoDesk 3DStudio (.3ds)
• MultiGen OpenFlight (.flt)

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Scene
DCS
Light
Group
Switch
SCS
Geode
Geode
Geode
Geode
DCS
Light
Sequence
pfScene - root node of a scene graphpfGroup -
generic grouping nodepfSCS - a transformation
which does not changepfDCS - a transformation
which can changepfSwitch - selects children to
be activepfSequence - cycles through a series of
children
Geode
Geode
Geode
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Show program (simple.c)
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DCS
A DCS can be updated by using the setTrans,
setRot, setScale, and setMat methods. The order
of effect is S R T. pfDCS dcs ...
dcs-gtsetTrans(transx, transy, transz)
dcs-gtsetRot(heading, pitch, roll) // RPH
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Show program (animation.cpp) Show program
(navigation.cpp)
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In-house libs - DDTk
Performer/CAVELib
DDTk Primitives
DDTk Services
DDTk Managers / Tools
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Links