Building Virtual Environments that are Reconfigurable, Scalable, Extensible with DIVERSE

The DIVERSE Course
May 20-21, 2002

John Kelso, Lance Arsenault

Abstract

This class will teach you how to construct Device Independent Virtual Environments- Reconfigurable, Scalable, Extensible (DIVERSE) applications. DIVERSE is comprised of two C++ application progamming interfaces that provide tools to write Performer based applications which can be run on a CAVE^TM, ImmersaDesk^TM, HMD (head mounted displays), desktop and laptop without modification of the applications code.

Prerequisites

Familiar with Performer^TM or simular scenegraph graphics APIs.
Familiar with C++, make, and shell programming in a UNIX like environment.

Day 1: section 1: 8:30am-10:15am

Brief Description and Razzle Dazzle-Demos

Objective:: Describe and demonstrate what DIVERSE can do, without details; hopefully motivates to learn

Very brief description of DIVERSE
- free open-source
- very modular, reconfigurable, extensible
- documention on the web, and in the packages
  - goto www.diverse.vt.edu
    - see homepage
    - see releases
    - see docs
    - see course notes
- DTK
  - non-graphics, including network services, hardware interfaces
  - C++ API
  - 50 programs (19 GUI, 31 non-GUI)
- DPF
  - device independent graphics built using Performer
  - C++ API
  - diverifly program and 4 others
- DGL
Performer-town on Desktop

show desktop navigation- the default- show heads-up, navigation control

% cd /usr/share/Performer/data/town/

% diversifly \    --origin 2567.215576 2392.712891 2 -92.218323 0.0 0.0 \    --length 0.9 town_ogl_pfi.pfb

show simulator navigation and features: toggle objects, jump view

% export DPF_DSO_FILES=desktopCaveSimGroup

% diversifly \    --origin 2567.215576 2392.712891 2 -92.218323 0.0 0.0 \    --length 0.9 town_ogl_pfi.pfb

add collision detection and terrain following

% export DPF_DSO_FILES=desktopCaveSimGroup:collisionDetection

% dtk-floatSliders walk -n 1 -s 0 0.001 10.001 1 -l Height &
% diversifly \    --origin 2567.215576 2392.712891 2 -92.218323 0.0 0.0 \    --length 0.9 town_ogl_pfi.pfb
Shiny cow on Desktop

back to the defaults

% unset DPF_DSO_FILES

% cd /usr/share/Performer/data/

% diversifly --length .25 --origin 2 0 16 0 -90 0 shinycow.obj

add a flashlight- can't use default any more

% export DPF_DSO_FILES=desktopCaveSimGroup:wandLight

% diversifly --nolights --length .25 --origin 2 0 16 0 -90 0 shinycow.obj

record navigation

% export DPF_DSO_FILES=desktopCaveSimGroup:wandLight:playbackWrite

% diversifly --length .25 --origin 2 0 16 0 -90 0 shinycow.obj

playback navigation

% export DPF_DSO_FILES=desktopCaveSimGroup:wandLight:playbackRead

% diversifly --length .25 --origin 2 0 16 0 -90 0 shinycow.obj
Performer-town in CAVE

use the VT CAVE with wand/joystick navigation

% cd /usr/share/Performer/data/town/

% export DPF_DSO_FILES=vtCaveGroup
% diversifly \ --origin 2567.215576 2392.712891 2 -92.218323 0.0 0.0 \ --length 0.9 town_ogl_pfi.pfb

add collision detection and terrain following

% export DPF_DSO_FILES=vtCaveGroup:collisionDetection

% dtk-floatSliders walk -n 1 -s 0 0.001 10.001 1 -l Height &
% diversifly \ --origin 2567.215576 2392.712891 2 -92.218323 0.0 0.0 \ --length 0.9 town_ogl_pfi.pfb
Shiny cow in CAVE

back to defaults in CAVE

% cd /usr/share/Performer/data/

% export DPF_DSO_FILES=vtCaveGroup
% diversifly --length .25 --origin 2 0 16 0 -90 0 shinycow.obj

add a flashlight

% export DPF_DSO_FILES=vtCaveGroup:wandLight

% diversifly --length .25 --origin 2 0 16 0 -90 0 shinycow.obj

record navigation

% export DPF_DSO_FILES=vtCaveGroup:wandLight:playbackWrite

% diversifly --length .25 --origin 2 0 16 0 -90 0 shinycow.obj

playback navigation

% export DPF_DSO_FILES=vtCaveGroup:wandLight:playbackRead

% diversifly --length .25 --origin 2 0 16 0 -90 0 shinycow.obj
Using DTK shared memory to mix things up

use sliders to put data into memory

% cd `dpf-config --source`/examples/shMDyn/diffEq0/

% dtk-floatSliders -n 6 position -s 1 0.5 3 0.95 -s 3 -180 180 0 \ -s 4 -180 180 0 -s 5 -180 180 0 -l x y z h p r &

read the data, queued

% xterm -e dtk-readFloats position --queue &

run a program that uses the data to position an object

% ./render &

use the sliders to look at the data

press the "update continuous" button in the slider window

look at the data with a virtual oscilloscope

% dtk-floatScope position -s position 1 -1 3 -s position 2 -1 3 -s position 3 -180 180 \ -s position 4 -180 180 -s position 5 -180 180 &

run a program that writes data into memory, calulated real-time

% ./diffEq

run a program that writes data into memory from a file

% cd `dpf-config --source`/examples/shMDyn/playback/

% ./playback playdata
Using DTK remote shared memory

instructor's machine sends out CAVE and navigation data

% cd /usr/share/Performer/data/town/

% export DPF_DSO_FILES=desktopCaveSimGroup:navDTKOutput:caveDTKOutput

% diversifly --origin +2567.215 +2392.712 +2.00000 -92.2 +000 +000 \ --length 0.9 town_ogl_pfi.pfb &

% a=caveSimDisplay:xkeyboardInput:caveSim:caveDTKInput:dtkNav

% export DPF_DSO_FILES=$a:setHeadView:toggleObjectsGroup:debugHeadsUp

% diversifly --origin +2567.215 +2392.712 +2.00000 -92.2 +000 +000 \ --length 0.9 town_ogl_pfi.pfb &

% dtk-floatScope head -s head 3 -180 180 -s head 4 -180 180 -s head 5 -180 180 &

% dtk-floatSliders head -s 3 -180 180 0 -s 4 -180 180 0 -s 5 -180 180 0 -l x y z h p r &

% dtk-gnomonDisplay head &

transparently networked- network with shared memory

% dtk-server -d

% /sbin/ifconfig | grep Bcast

% dtk-connectRemoteSharedMem head IP_ADDRESS &

% dtk-shutdownServer

Day 1: section 2: 10:30-noon

Running Command line programs

Objective:: Be able to use DIVERSE without programming

diversifly

load Performertown data, knowing nothing about it

% cd /usr/share/Performer/data/town/

% diversifly --center town_ogl_pfi.pfb

turn on the heads-up display

press "?" with the mouse in the graphics window

navigate down to the ground and find a place you like

press "+" and "-" to double or half speed

use the left mouse button to go forward/back

use the middle mouse button to raise/lower

record this place as a new origin

press ">" to dump your position to standard output

"cut" the XYZHPR of the POSITION line

press "Esc" to exit

paste this into a new diversifly command

% diversifly --origin +2567.215 +2392.712 +2.00000 -92.2 +000 +000 \    town_ogl_pfi.pfb

run it in the simulator

% export DPF_DSO_FILES=desktopCaveSimGroup

% diversifly --origin +2567.215 +2392.712 +2.00000 -92.2 +000 +000 \    town_ogl_pfi.pfb

use the 10' simulator cube to size the units

press and hold "s" then press "c" twice and release "s"

press space and move mouse to fly around- how's it look?

the world seems a bit too big- change its size

press and hold "s" then press "c" twice and release "s"

press space and move mouse to fly around- how's it look?

make one model unit be 0.9 meters

% diversifly --origin +2567.215 +2392.712 +2.00000 -92.2 +000 +000 \    --length 0.9 town_ogl_pfi.pfb

try another- the shiny cow

% unset DPF_DSO_FILES

% cd /usr/share/Performer/data/

% dpf-transform --center --bound shinycow.obj /tmp/foo.pfb

% cd /tmp/

% diversifly --origin 0 -20 0 0 0 0 foo.pfb

% dpf-transform --euler 0 90 0 foo.pfb bar.pfb

% export DPF_DSO_FILES=desktopGroup:centerSwitchPivotNavMod:toggleBoundingSphere

% diversifly --origin 0 -20 0 0 0 0 bar.pfb

press "B" to see bounding sphere

press "?" for the heads-up and "p" to switch to trackballNav

use middle button to spin!

% export DPF_DSO_FILES=desktopCaveSimGroup:wandLight

% diversifly --nolights --origin 0 -5 0 0 0 0 bar.pfb

press "w" to see the wand, and press "Alt" and move the mouse

DTK commands

% dtk-<TAB><TAB>

% dtk-server --help

% dtk-connectRemoteSharedMem --help

% dtk-loadService --help

% dtk-pingServer

% dtk-server

% dtk-pingServer

% dtk-loadService hello

% dtk-readStrings hello -q

% dtk-unloadService hello

% dtk-shutdownServer

% dtk-destroySharedMem

Day 1: section 3: 1:15-2:45

DIVERSE API and programming using examples

Objective:: Understand, move, modify, make DIVERSE programs based on examples

dpf-config, dtk-config and portable Makefiles and scripts

% dpf-config

% dpf-config --libs

% dpf-config --source

% cd `dpf-config --source`/examples/

% cd minimumHelloWorld

% cat Makefile

% cd ..; mkdir /tmp/hello

% cp minimumHelloWorld/* /tmp/hello

% cd /tmp/hello

% make

% ./hello
display

describe scenegraph
describe display class diagram
% cd `dpf-config --source`/contrib_DSOs/

% less vtCaveDisplay.C

% cd /tmp/hello

% export DPF_DSO_FILES=hyperDisplay:xkeyboardMouseInput:toggleObjectsGroup:trackballNav

% ./hello
two versions of hello.C

% cd `dpf-config --source`/examples/minimumHelloWorld

% cat hello.C

% cd ../helloWorld/

% less hello.C
a DPF DSO that writes navigational data

% cd `dpf-config --source`/DSOs

% less navDTKOutput.C
there is a similar DSO that reads navigational data

% cd `dpf-config --source`/DSOs

% less dtkNav.C
run writer and reader

% export DPF_DSO_FILES=desktopGroup:navDTKOutput

% diversifly sub.pfb gnomon.pfb &

% export DPF_DSO_FILES=desktopGroup:dtkNav

% diversifly sub.pfb gnomon.pfb &
input

explain 2 tiered architecture, 6 logical input types

example: mouse pointer- polled, queued, as reader specifies

% cd `dpf-config --source`/examples/mouse

% less pollPointer.C

% diff pollPointer.C queuePointer.C

% ./pollPointer

% ./queuePointer

Day 1: section 4: 3:00-4:30

New features, Open lab

DGL, the DIVERSE interface to OpenGL, with Chris Logie
Using DIVERSE with OpenGL Volumizer, with Alex Kalita
The InterSense wireless tracking system, with Dean Wormel
Hands-on time in the CAVE and lab to work on your data

Day 1: section 5: 6:00

Barbeque at Ron Kriz's

Day 2: section 1: 8:30-noon

Open lab

more hand-on lab time
tracker calibration, also dtk-getTrackd

Day 2: section 2: 1:15-4:30

Breakout sessions

Install DIVERSE on your laptop
Converting VRML and 3D model scenegraphs
Lecture on user interface development
More hands-on time in the CAVE and lab