Post on 03-Jan-2016
Virtual Instrument Design and Animation
Cynthia BruynsRobert TaylorCarlo Séquin
University of California at Berkeley
AimAim
To provide an environment for evaluating the
sound qualities of modeled simple idiophones
Images courtesy of Steve Reinmuth
AimAim
To recreate the object’s sound in an interactive environment
To be able to use these sounds to extend synthesis for computer music
Modeled Objects Mode Activation
Previous Sound Generation ResearchPrevious Sound Generation Research
StochasticSerra, X. et al. 1990
Cook, P. 2001
Texturesvan den Doel, K. et al.
2001
Di Fillipo, D. et al. 2000
AnalyticSmith, J. 1992
Cook, P. 1995
ModalMorrison, J. et al. 1993
O’Brien, J. et al. 2001
Methods for sound synthesis for graphics
Geometric ModelsGeometric Models
Simple or complex shapes
Multiple resolutions are generated
Can use thin or solid models
Physical ModelPhysical Model
Modal FormulationModal Formulation
Mode Shapes (exaggerated)Mode Shapes (exaggerated)
Modal ActivationModal Activation
Load model geometry into viewer program. Choose materials parameters. Select several strike locations on the model
– and map to keys of a midi keyboard.
PLAY ! – Key velocity determines intensity of strike.
Interactive Sound GenerationInteractive Sound Generation
Software created as an Audio Unit plug-in
Can be used in AU host applications
This allows for sound generation in a composing environment
Strike Location
Sound ValidationSound Validation
Synthesized sounds were compared with actual object sound generation Square plate
Aluminum
Steel
Rectangular plate
Aluminum
Odd shaped plates
Aluminum Model Real
Measurement SetupMeasurement Setup
Sound dampened room
Selection after transients
FFT analysis of identical time intervals
Time (seconds)
Fre
quen
cy (
Hz)
Am
plitu
de (
dB)
AnalysisWindow
?
Square (Aluminum)Square (Aluminum)
Frequency (Hz)
Sou
nd P
ress
ure
Leve
l (dB
/Hz)
60
40
20
100 200 500 1000 2000
Materials
Model
Square (Steel)Square (Steel)
Frequency (Hz)
Sou
nd P
ress
ure
Leve
l (dB
/Hz)
60
40
20
100 200 500 1000 2000
Materials
Model
Rectangle (Aluminum)Rectangle (Aluminum)
Frequency (Hz)
Sou
nd P
ress
ure
Leve
l (dB
/Hz)
60
40
20
100 200 500 1000 2000
Materials
Model
?
Frequency (Hz)
Sou
nd P
ress
ure
Leve
l (dB
/Hz)
60
40
20
100 200 500 1000 2000
Materials
Model
Odd Shaped Plates - “S”Odd Shaped Plates - “S”
Odd Shaped Plates - “G”Odd Shaped Plates - “G”
Frequency (Hz)
Sou
nd P
ress
ure
Leve
l (dB
/Hz)
60
40
20
100 200 500 1000 2000
Materials
Model
Demo PlateDemo Plate
Demo Odd ShapeDemo Odd Shape
Summary and DiscussionSummary and Discussion
System for generating “ringing” sounds
More “natural” => more interesting
Real-time generation of strike-sounds.
System may become predictive enough to allow interactive design of new “bells”
Real-time shape modifications an re-analysis ?
Extensions:
Non-linear phenomena during initial strike
Include coupling with environment (air).
AcknowledgementsAcknowledgements
Apple Computer
Ruzena Basjcy
David Bindel
Jon Drukman
Justin Maxwell
James McCartney
Kim Silverman
Bill Stewart