Transcript PowerPoint Presentation - Navigable Space

Some Thoughts on
Composing a Navigable Space
Dr. Dan Hosken
Assistant Professor of Music
California State University, Northridge
Presented at:
SEAMUS 2004
San Diego, CA
March 25, 2004
Definition

Navigable Space: a real or virtual
environment that is traversed by a user
or surrogate. Aspects of that navigation
such as position, velocity, acceleration
and “effort” serve as input to an
interactive music system.
Related Work
Gerhard Eckel (esp. Camera Musica)
(http://viswiz.gmd.de/~eckel/publication
s/eckel97b/eckel97b.html)
 Char Davies (esp. Osmose)
(http://www.immersence.com/)
 Tod Machover’s Brain Opera (esp. the
“Harmonic Driving” game)
(http://brainop.media.mit.edu/)

Scale
Concept realizable on different scales
 Videogame-style (keyboard/joystick)
 Fully immersive VR environment
 “Sound Space I” is currently realized on
the videogame-style scale
 NavigationSound Parameter
mappings should scale

Physicality
“Character” subject to some physical
laws
 Expenditure of energy is special
concern
 “Physicality” implies a sense of physical
reality— not necessarily subject to literal
laws of physics.

Parameter Mapping Levels

Direct: motion directly affects aural result
(e.g., localizing a sound source to the
onscreen character)
 Indirect: motion affects a higher level entity
(e.g., causes a group of tones to brighten or
distort)
 Abstract: motion tendencies affect the
tendencies of higher level entities (e.g.,
sustained activity affects the pitch evolution of
the materials)
Sound Space I Technology
Macromedia’s Director multimedia
authoring software
 Niels Gorisse’s CPS—patchable
realtime synthesis software (Max/MSPish) based on MPEG-4 SA (Csound-ish)
 CPS is also implemented as a Director
Xtra—CPS patches can be saved as
Lingo scripts

CPS Interface
CPS Patch as Lingo script
-- Subpatch: 'RMShaper4'
-- Subpatch: 'RingModOscil'
set sinus174 to CPSgetObject("sinus")
set multiply175 to CPSgetObject("*")
set multiply176 to CPSgetObject("*")
CPSOBJConversate(multiply176,"_UP")
CPSOBJConversate(multiply176,"_UP")
CPSOBJConversate(multiply176,"_UP")
set multiply177 to CPSgetObject("*")
CPSOBJConversate(multiply177,"_UP")
CPSgetConnection(multiply175,40,sinus174,20)
CPSgetConnection(sinus174,30,multiply176,10)
CPSgetConnection(multiply176,30,multiply177,11)
Setting CPS Parameters
CPSOBJkin(polytab4,5.0,0)
CPSOBJkin(dur4,250.0,0)
CPSOBJkin(att4,50.0,0)
CPSOBJkin(dec4,50.0,0)
CPSOBJkin(sus4,1.0,0)
CPSOBJkin(rel4,100.0,0)
CPSOBJkin(numberField266,58.0,0)
CPSOBJkin(numberField267,0.88,0)
CPSOBJkin(rmfreq41,1.0,0)
CPSOBJkin(rmamp41,0.5,0)
CPSOBJkin(rmfreq42,2.0,0)
CPSOBJkin(rmamp42,0.0,0)
CPSOBJkin(rmfreq43,3.0,0)
CPSOBJkin(rmamp43,0.0,0)
CPSOBJkin(rmfreq44,3.2,0)
CPSOBJkin(rmamp44,0.0,0)
CPSOBJkin(rmfreq45,3.7,0)
CPSOBJkin(rmamp45,0.0,0)
--polynomial table
--note duration
--Attack (ms)
--Decay
--Sustain Level
--Release
--unlabeled numberfields
--Frequency factor for ring mod 1
--Amplitude of ring mod 1
--Frequency factor for ring mod 2
--etc.
Sound Space I Visual Interface
Cindercone, Lassen National Park, CA
Sound Space I Visual Interface

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Invisible overlaid shapes delineate “hot” and
“cool” zones
Asteroids-style ship is controlled by arrow
keys plus a ‘F’ast key
Friction factor is applied to ship movement—
higher in hotter zones, lower in cooler zones
Doors to lead to other landscapes (future)
Invisible, moving trap doors (future)
Sound Space I Mapping: Engine
Simple phasor at nearly sub-audio run
through low-pass resonant filter
 Largely “Direct” mappings
 Horizontal position  Pan
 Speed  Frequency (ca. 16 to 20 Hz)
 “Effort”  Filter Cutoff

Sound Space I Mapping: Shaper

Non-linear waveshaping instrument with ring
modulation
 Largely “indirect” and “abstract” mappings
 Note-level parameters include ASDR
envelope parameters, distortion index, and
ring modulation frequency factor
 Notes are played automatically in a regular
rhythm with pitches chosen from tables
Sound Space I Mapping: Shaper
Global parameters include note
duration, inter-onset time, inter-onset
randomization amount
 Pitches are chosen from tables
 Transposition determined by effort level
associated with zone
 Effort associated with various zones
determine most parameters

Temporal Shape: Activity Level
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User actions determine much of the temporal
evolution
An “activity level” is calculated from the user’s
persistence in various zones
Currently the rate of activity level
accumulation is externally set
Activity level determines the pitch collection
“expansion” and the octave offset
Each landscape may have a different balance
of “hot” and “cool” zones
[email protected]
http://www.csun.edu/~dwh50750/