Projects Presentations: Sound and Animation Dates: Week 9: Wed, Feb 14 Week 10: Mon, Feb 19 Finals Week: Tues, Feb 27 (2:45-4:45) 15 minutes / presentation Schedule now on Web Please send me choice of time/day ALL PRESENTATIONS HAVE BEEN SCHEDULED!!! PRESENTATIONS START ON WEDNESDAY Assignments Plan Assignment 1 -- Framework Today: Assignment 2 -- Keyframing Last lecture: Sound and Animation Most have been graded. Wednesday Presentations -- Day 1 Assignment 3 -- Billiards Next Monday 50% graded Presentations -- Day 2 Assignment 4 -- Group Motion Next Wednesday To be done Wednesday-Thursday NO CLASS Assignment 5 - Walking Feb 27th (Finals week) Due 2/16 (Friday) Presentation -- Day 3 NOTE: Dropbox close dates have been fixed. LAST DAY TO HAND IN STUFF. Thinking About Spring? Thinking About Spring Applications in Virtual Reality (4003-590-09 / 4005-769-09) Procedural Shading The goal of this course is to introduce students to the architectures and mechanisms of procedural shading and to teach them how to use shaders Virtual Theatre effectively in creating stunning visual effects. A distributed computer system whereby performers, stage crew, and audience can be in physically separate places yet share in the same live theatrical performance. Components Components Advanced RenderMan Torque Gaming Engine Real time shaders (Cg) moCap devices Lecture + Lab/Studio Game networking Actual shaders form artists specs. Details Details 4003-590-09 / 4005-769-09 TR 2-4 (ICL6) 4003-590-01 / 4005-769-01 TR 4-6 (ICL6) Please contact Joe Geigel (jmg@cs.rit.edu) for details PRE-REQ: Computer Graphics II 1
Jobs, Jobs, Jobs Jobs, Jobs, Jobs Full time position Demiurge (Boston area) Game company Interns, co-ops, full-time Intel Programmers who likes games GPU validation Experience in 3D and/or hardware www.demiurgestudios.com May Graduation date Several alum there Send resume to me, I will forward. E-mail me w/resume if interested. Jobs, Jobs, Jobs Jobs, Jobs, Jobs Possible co-op position Upcoming company presentations: Google -- Tues, Feb 13, 4-6pm (70-1400) Possible part-time work Paychex -- Thurs, Feb 15, 2-4pm (in Webster -- RSVP required) Intel -- Fri, Feb 16, noon-3pm (COE, Erdle) Interactive Collaboration Envroments Lab in See posting on my office BB for info CASCI Collaboration Technology Specialists Video / audio / communication over Internet 2. http://www.rit.edu/~rc/jobs.html Jobs, Jobs, Jobs Projects Final Reports US Air Force Research Labs Note that final reports / code are Rome (New York, not Italy) SEPARATE grading components Summer Positions Final reports/code are due on the last day Applications due February 28th of class (Feb 27th) Very hard deadline Note this is a hard deadline Dropbox is set up for report and code submissions. E-mail me for more info. 2
Projects Plan for today Final Report Sound and Animation Describe as if you were passing on your code to the next victim. Sections Problem/Project Description Approach Implementation Overall System Architecture. Overall Program Architecture Description of major data structures / objects Results / User Documentation Future Enhancements Appendix -- All Code listings Motivation Films Motivational Film Animations by Wayne Lytle More Bells and Whistles (1990) Visualization Guru at Cornell Theory Center Lytle wrote the the code for each band member Quit to start Animusic in 1995 Motion is MIDI controlled First of several Animusic pieces to be shown at SIGGRAPH Motivational Film Motivational Film Pipe Dream (2001) Train Wreck (2003) Animusic Martin Burolla Can’t See too much Animusic From animation class (20022) Sound drives motion 3
Sound and Animation Sound Issues in Sound and Animation What is sound? Sound Generation From webster.com What do we play? mechanical radiant energy that is transmitted by longitudinal pressure waves in a material Sound Synchronization medium (as air) and is the objective cause of When do we play? hearing Spatial Sound Where do we play Sound Remember this? What is sound? Spatial vs frequency domains Sound can be described as a 1 dimensional Most well behaved functions can be signal in time described as a sum of sin waves (possibly offset) at various frequencies Describing a function by the contribution sound = f(t) (and offset) at each frequency is describing the function in the frequency domain Sound Sound A mathematical description of an audio signal: � f ( t ) A sin( 2 t ) = � � � + � i i i i 0 = Contribution/amplitude frequency phase Foley/VanDam 4
Sound: Loudness Sound: Pitch Looking at sound in the temporal Looking at sound in the frequency domain domain. Sound can be described as a 1 dimensional Humans “hear” sounds because of signal in time periodicities in the audio signal. Humans perceive frequency as the sensation of pitch. Signal values represent amplitude. Humans can perceive pitches due to periodicities ranging from 20 – 20000 We perceive the effect of amplitude as vibrations / sec (Hz). loudness. Sound: Pitch Sound: Timbre Tone quality of a sound Remember our discussion of CD audio Formally defined as sampling rate of 44,100 samples/sec Characteristic of sound not due to Δ = 1 sample every 2.26x10 -5 seconds amplitude and pitch. CDs can accurately reproduce sounds with Also defined frequencies as high as 22,050 Hz. Quality of tone that distinguishes between musical instruments Sound shape Sound: Timbre Sound: Summary Timbre is the perception of the “spectral Physical Perceptual makeup” of a signal. Characteristic Characteristic Adding non-fundamental frequency to the Amplitude Loudness signal. Frequency Pitch Another annoying audio applet – Timbre Spectral “shape” Timbre 5
Sound Generation Sound Generation So how does one generate sound for When talking about digital (sampled animation? sound) Easiest means The process of digitizing is called pulse code modulation (PCM). Recording / Sampling -- Still the primary means for sound generation in the film industry PCM == sampled sound Using sampled sound – Still the primary means WAV for sound use in games. AIFF MP3 (compressed PCM) Sound Generation Sound Generation Subtractive Synthesis Additive Synthesis � � f ( t ) A sin( 2 t ) f ( t ) A sin( 2 t ) = � = � � � + � � � + � i i i i i i i 0 i 0 = = Define values for A i , ω i , and φ i Start with noise (equal energies at all Calculate sin and add frequencies) Alternately, do in the addition in frequency Subtract contribution of frequencies space. from noise. Sound Generation Sound Generation Granular Synthesis Using physically based models Like particle system SIGGRAPH 2001 Videos Combine a multitude of sound “grains” into a sound events Questions 6
Sound Synchronization Sound Synchronization Sound driving motion Sound must be synchronized to the MIDI motion Designed as a communication mode between Methods: sythesizers, samplers, instruments, computers Sound events Motion driving sound Pitch Defining Sound events Devices Deriving timbre from motion Used by Animusic in creating their videos Sound driving motion Example video from Bingo guys. Spatial Sound 3D Sound Sounds (and listeners) have spatial positions Making sounds appear as if they are 3D sound emitted from a given position Making sounds appear as if they are emitted from a accounting for listener position given position accounting for listener position Head related transfer functions (HRTF) Reverberation Filtering of sound based on reflection off of environment Audio cubes / surround sound Doppler Effect Strategic placing of speakers Change in pitch due to moving objects 3D Sound: HRTF 3D Sound: HRTF a description of all the physical cues of sound localisation. Implemented as filters function of four variables: ie three space coordinates and frequency. Determined by measurement Anderson/Casey 7
3D Sound: HRTF 3D Sound: reverberation Like light, sound can be seen as traveling in 3D environment in rays. Unlike light, sound travels much slower Speed of sound: Speed of light Anderson/Casey 3D Sound: reverberation 3D Sound: reverberation Examples Reverberant sound is the collection of all the From BKL Consultants Ltd. reflected sounds in an (http://www.bkl.ca/page131.htm) enclosed space No reverb Acoustics 0.8 sec reverb time Reverb Time = time 1.5 sec reverb time required for sound to 5.0 sec reverb time decay one millionth of the original power One more SIGGRAPH video 3D Sound: Doppler effect 3D Sound: Doppler effect Non-annoying applet break 8
Recommend
More recommend
