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Upcoming DeadlinesHomework #11 Building a Scene in MayaDue Tuesday, November 22nd (Only class meeting next week)20 points (10 points if late)
For full schedule, visit course website:ArtPhysics123.pbworks.comPick up a clicker, find the right channel, and enter Student ID1Homework #11For this assignment you will create a simple scene; the assignment that follows will be to light the scene in a variety of ways.
In both of these assignments you will be using Autodesk Maya, a popular software application used in animation.
You can download a 30-day trial version of Maya from the Autodesk website.2Homework #11The scene that you create in this assignment consists of a floor, a single wall in the background, and some objects in the foreground.
Those objects need to be arranged so that they create the shape of the initials of your name.
Position the two letters so that they rest on the floor or on each other; do not have themtouching the vertical wall.3Homework #11This simple scene was created by Candice Downey.
4Homework #11Alternative non-Maya Assignment: If you are unable to use Maya then create a scene like the one described above using real objects (blocks, books, etc.) and photograph the scene. In next week's assignment you will light this scene in a variety of ways so be sure that you can recreate it for that assignment.
This assignment is due by 8am on Tuesday, November 22nd
20 points (if late, 10 points)5Survey QuestionHow did your stop-motion character animation turn out?Very goodGoodFairPoorDidnt complete it
Review QuestionThe longer strings of a harp and the longer pipes of an organ produce sounds with:
Higher frequenciesLower frequenciesEqual frequencies
7Wavelength and FrequencyB) Lower frequenciesLonger strings and pipes produce sounds with longer wavelengths and thus lower frequencies.For example, if the length is doubled then the frequency is halved, lowering the note by one octave.
Men and women typically sing an octave apart.C5C4High noteLow note8Review QuestionWhen the forced vibrations match an objects natural frequency the oscillations grow in amplitude due to synchronized transfer of energy into the vibrating object.This is called:SpectrumAcoustic BeatSurgingResonanceHarmony
9Acoustic ResonanceD) Resonance
If amplitude of the sound is sufficiently large, resonant vibrations can shatter a wine glass.
10Review QuestionA musical instrument playing a single note produces not just that notes frequency but others as well, mostly overtones.
The unique signature of an instruments spectrum is called:
11Why Instruments DifferC) Timbre
The unique spectrum of frequencies for a musical instrument gives that instrument a unique signature, which is called the instruments timbre (or quality).
Playing this note (196 Hz)12Timbre of a Material
Spectrum of waves will be different for different materials due to density, viscosity, surface tension, depth of the fluid, etc.Gushing Oil Wellhttp://www.youtube.com/watch?v=pDyqhOL1ePUJello waves
13Optics & LightingPart I: Ray Tracing
14LightingLighting is important in all the visual arts, from painting to cinematography.
The Orrery, Joseph Wright (1766)
Humphrey Bogart in The Maltese Falcon (1941)15Up (2009)Lets look at how lighting in used in a a scene from Pixars Up.
Key Lighting (One-Point)Simplest type of lighting is with a single dominant light source, called the key. Traditionally, this light source is located on the left side of the scene.17Utah TeapotThe Utah teapot or Newell teapot is a 3D computer model which has become a standard reference object (and an in-joke) in the computer graphics community. It is a mathematical model of an ordinary teapot of fairly simple shape, which appears solid, cylindrical and partially convex.
The teapot model was created in 1975 by early computer graphics researcher Martin Newell at the University of Utah.
Cast Shadows & Form ShadowsForm ShadowCast Shadow19Cast Shadows
Size and sharpness of a cast shadow depends on: Size of the light source Distance from light to object Distance from light to wall20Cast Shadow for Directional LightUMBRAObjectWallA directional light has parallel light rays so the cast shadow is simple to trace on the wall.Dark shadow called the umbra.Shadow is sharp (not fuzzy).Creating Directional LightLight sources, such as bulbs, send light in all directions; directional lighting is created with mirrors or lenses to form the light into a beam.
Barn doorsCast Shadow for Point Light SourceUMBRALight source(Point)ObjectWallShadow is sharp (not fuzzy).Size of shadow depends on:* Distance from the light to object* Distance from object to wall Light rays spread out from a point light source, such as a bright light bulb or a candle.Film Noir Shadows
Shadow Of A Doubt (1943)M (1931)Film noir makes extensive use of cast shadows, manipulating their size for dramatic effect.
I Confess(1953)Cast Shadow for Area LightsUMBRAPenumbraPenumbraLight sourceObjectWallRays from a large light source to wall to map out location of deep shadow (umbra) and fuzzy shadow (penumbra).The larger the light source, the smaller the umbra.Umbra and PenumbraAn ant on the ground standing in the penumbra could see part of the sun.
Standing in the umbra part of the shadow, the ant wouldnt see the sun at all.
No ShadowPenumbraUmbra26Solar ShadowsUMBRAPenumbraSunObjectThe width of the penumbra for a shadow cast by the Sun equals about 1% of the distance from the object to its shadow.FloorAngle = degree()DistanceDiagram is not to scaleLIGHTExample: If an object is 9 feet (108 inches) from the ground, the penumbra is a little more than 1 inch wide.27Penumbra SizeNotice how the size of the shadows penumbra increases as the shadow gets farther from the base of the tree.
Very far from the base the penumbras on each side meet and theres no more umbra.
28Solar Eclipse Seen from Space
. And another
Light Intensity & Distance
The intensity of light decreases as we get farther from the light source.For a point light the intensity decreases quadratically, that is, at twice the distance you have a four times less intensity.The light gets weaker because it is spread over a larger area.31Demo: Perspective CardsHold large card at arms length.Close one eye then hold small card at a distance such that it is same size as large card.That distance will be half way between your eye and large card.11234Arms lengthHalfArea & DistanceThese four figures are equally spaced indistance and, in perspective,you are standing that distance from the first.At twice the distance,the face is the size.At four times the distance face is 16th the size.Light Intensity & AngleAs angle between the light and a surface increases, the intensity of the light on the surface decreases because it is spread over a larger area.7 light rays hit surface 5 light rays hit surface 34Seasons of the YearNorthern Hemisphere is warm in July because Earth is tilted towards the Sun.Southern Hemisphere is cold in July since its tilted way from the Sun.
The seasons are reversed in January.
Equator35Lighting and Dimension
Intensity of light striking a surface varies with angle so the gradient created by a key light is a strong visual cue of an objects curvature and shape.36Form Shadow for Point Light SourceLight source(Point)ObjectThe form shadow is completely dark if point source is the only light source (i.e., no ambient or reflected light). Object is brightest where the rays hit head-on and dims going up to the terminator.TerminatorForm Shadow for Area Light SourceLight source(Area)A B CView from AView from BView from CTerminator widens into a penumbra for an area light.Ambient Light
DirectDirectDirectAmbientAmbientAmbientMost lighting is indirect, coming not from a light source but from reflections off of other surfaces.39
Fill LightingKeyFillKey+FillWith two-point lighting the fill light softens the contrast by adding ambient light.40
Rim LightingKey+FillRimKey+Fill+RimAdding a rim light shining from behind distinguishes the foreground objects from the dark background.41Three-point LightingRimKey+Fill+RimThree-point lighting (Key, Fill, and Rim) is a formula that Hollywood has used for years.
From Casablanca (1942)Three-point lighting usually looks good but sometimes too good, that is, it seems fake.42Inconsistent Shadows
The Birth of the VirginFra Carnevale, 1467The perspective in this painting is pretty good but whats wrong with the shadows?
The Birth of the VirginFra Carnevale, 1467Long shadowsfrom left to rightNo shadows?Rising shadows?Downward shadow?Variety of errors yet not immediately noticeable.44Inconsistent Shadows
Frames of Reference, A. Garcia (2000)45Inconsistent Shadows
Reference photos illustrate why the shadows are inconsistent in the final image.46Inconsistent Shadows
This fake cutting that circulated during the 2004 Presidential primaries combined a photo of John Kerry was taken 1971 with one of Jane Fonda taken in 1972.
The form shadows on their clothes are clearly inconsistent.47Next LectureReflectionHomework #11 (Building a Scene in Maya)Due next Tuesday Please turn off and return the clickers!48