Camera and Lighting for Animation

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Camera and Lighting for Animation

• Amy Gooch
• CS 395 Intro to Animation
• Summer 2004

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Animations

• The Cathedral
• Parkland College Film Reel
• http//www.anzovin.com/javanoir.html

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Think about film lighting
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Reality!
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Visual Meaning

• Cumulative effects of the arrangement of the
  basic elements
• The perceptual mechanism that is universally
  shared by humans

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Visual Literacy

• Design principles or composition
• unity, balance, emphasis, scale
• Design elements
• color, tone, line, texture

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Value
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Value
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Value
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Color
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Color
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Color
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Shape
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Texture
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Position and Direction
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Composition

• Rules
• Breaking the Rules

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Balance Eye Control

• Visual weight
• Physics, reality (gravity)
• Horizontal-vertical relationship
• Lack of balance disturbs us

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Symmetry
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Imbalance
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Cameras Viewpoint

• From Photography and Film -gt Computer Animation
• Mechanical devices -gt software simulation
• Removes limiation of space time

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Cameras

• Focus and capture light

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Camera and Scene Setup

• Where to put the camera
• How much to show within frame?
• When to move the camera?

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Camera Specifications

• Position
• Focal Length
• distance between focal point of lens
  and film plate
• Field of view
• horizontal viewing angle of scene created
  from focal point
• Film Plate, Aperature
• dimensions (width and height) for film plate, or
  gate
• F-stop
• focal length divided by diameter of lens (related
  to amount of light passing)

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Camera Position

• Catch the most expressive aspect

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Camera Angles
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Field of View
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Changing Focal Length

• Changes field of view
• with constant aperature

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Field of View
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Changing aperature

• Changes field of view
• with constant focal length

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Field of View
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How much to show?
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Camera Angles
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Depth of Field
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Depth of Field

• Simulate real camera lens focusing
• Provides strong sense of realism and
  believability
• No depth
  of field

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Depth of Field default in Maya
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How to get at right depth

• Use Measurement tools
• Create-gtMeasure Tools-gtDistance Tool

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Display-gtHeads Up Display-gtObject Details

• Distance From Camera information (current camera
  to selected object)

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Focus Distance 2.0
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Increase F-stop
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Increase Focus Region
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Change Focus Region to back
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Direction of Action

• Give the subject space to move

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More emphasis on objects that are

• Close
• Taller
• Repeated (chorus line)
• Only moving object
• Only still object

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When should the camera move

• To increase continuity
• To keep a subject within view

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Camera Motion
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Tracking vs TrackingZoom
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Lighting in animation

• Same goals as real world lighting
• Bringing out or pushing back shapes of visible
  objects from the cameras view
• Emphasize 3rd Dimension in a 2D image

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But it can do more

• Personality
• Feelings
• Happiness
• Sorrow
• Fear
• Etc.

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Lighting is hard

• Hard to make images photorealistic
• Harder still to convey emotions
• Best way to achieve goals is to have goals to
  start with

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Properties and components of light

• Also known as quality of light
• Intensity
• Direction
• Color
• Size

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Light Intensity

• Amount of light emitted from a source of light
• Example light a sphere in scene (changing
  intensity only)

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Light Intensity

• Under lit

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Light Intensity

• Light reflection is visible
• but too dark

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Light Intensity

• Objects visible
• Textures almost visible
• No statement

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Light Intensity

• All objects visible
• No light reflection
• Texture on third of sphere is lost

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Light Intensity

• All objects clear
• Spheres colors oversaturated
• Other objects oversaturating

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Light Direction

• Imagine a scene
• Black background
• Light of equal intensity and color is incident on
  a human face from all directions
• What do you see?

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Light Direction

• We recognize shape of an object because light
  rays of different intensities hit from different
  directions
• Paint object with highlights and shadows
• Direction of light can
• Enhance shape
• Emotion

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Lighting Direction can effect the shape
Lit from single light source to left of camera
see base on surface, folds, etc
Single light source directly behind camera Loose
detail in front because cast shadows are washed
out
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Lighting Direction can effect the mood..
Lit from below produces a dramatic effect
Menancing
Subtle Menacing
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Realistic lighting

• Comes from above

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Emphasizing characters

• Features
• Positive or negative influence on personality
• Lighting those features

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Emphasizing characters

• Features
• Positive or negative influence on personality
• Lighting those features

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Color of Light
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Color affect depth

• Cool color recede
• Warm colors advance
• Far objects lose color saturation (fog)

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Color and time of day
Early Morning
Mid-day-winter
Evening-summer
Gramps (modeled and textured by David Maas).
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Color and time of day
Summer Mid-day
Evening-summer
Illusion of Night
Gramps (modeled and textured by David Maas).
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Light Source Size Effects overall feeling of
scene

• Small very sharp distinct shadows (tension)
• Bigger softer shadows (relaxed)

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Basic Kinds of Lighting

• From film
• Key Light
• Fill Light
• Rim Light

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Key Light

• Primary light
• Placed to create highlights and shadows

http//www.andrew-whitehurst.net/3point.html
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Fill light

• Illuminate areas of image in shadow with key
  light
• Placed after and in relation to key light

http//www.andrew-whitehurst.net/3point.html
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Key and Fill

• Still missing right edges

http//www.andrew-whitehurst.net/3point.html
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Rim light

• Placed behind objects and angled so light glances
  off surface
• High intensity to create bright light around
  object
• Separate object from background

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Key Fill Rim
http//www.andrew-whitehurst.net/3point.html
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Project 3
Mood (change of character)
Hero
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Project 3

• Artistic (Optional)

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Color lights
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(Switch to web page)

• Rendering with Light
• Lights and shadows

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Ray Tracing

• http//www.cs.berkeley.edu/efros/java/tracer/trac
  er.html
• http//www.siggraph.org/education/materials/HyperG
  raph/raytrace/rt_java/raytrace.html

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Types of lights in Maya

• Ambient
• Point
• Directional
• Spot
• Area

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Ambient
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Point Light

• Create gt Light gt Point Light
• Light shines evenly in all directions from a
  single location
• Dependent upon position
• Independent of direction

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Point Light
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Point Light Properties

• Decay degree to which brightness decreases with
  distance from source
• None, Linear, Quadratic, Cubic (left to right,
  top to bottom)

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Moving Point Light to get Directional Light
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Directional Light

• Create gt Lights gt Directional Light
• Simulates light shining evenly in one direction
• Dependent upon direction
• Independent of position
• Similar to sun
• Useful as fill light

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Directional Light
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Spot Light

• Create gt Lights gt Spot light
• Simulates light shining evenly within a coned
  region from a single location
• Similar to point, but confined and directed by
  cone
• Dependent upon position and direction

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Spot Light
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Spot Light properties

• Decay brightness decreases with distance from
  source (same as point light)
• Dropoff brightness decreases from center of
  beam to beam edges
• Dropoff values 20, 40 (left to right)

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Spot Light Properties Cone Angle

• Angle of cone (radius) measured from cone middle
  to cone edge (0.0 180.0)
• Cone angle values 35, 55, 75, 95

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Spot Light Properties Penumbra Angle

• Angle measured from edge of cone to where
  intensity drops to zero (linearly)
• Light falls off gradually from edge of cone
  through penumbra angle
• Provides a softness to spot light edges Softness
  makes the spot lights actual location less
  obvious
• Positive values add to cone edge, negative values
  subtract from cone edge
• Penumbra angle values 10, 20, -10, -20

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Area Light

• Create gt Lights gt Area Light
• Simulates light emanating from rectangular region
• Like real lights
• Physically-based on distance
• Manipulate through standard transformation tools
  (scale, rotate, translate)
• Larger area lights (scaling) emit more light
• Increased rendering times

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Area Light

• Ray-traced, depth-mapped shadows

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Area Light

• Ray-traced, depth-mapped shadows, object with glow

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Shadows

• Shadows are created with.
• 1) Shadow casting light(s)
• Depth Map Shadows or Ray Trace Shadows on/off
  (attribute)
• 2) Surface(s) that cast shadows
• Render Stats attribute -gt Casts Shadows
  (checked/unchecked)
• 3) Surface(s) that receive shadows
• Render Stats attribute -gt Receive Shadows
  (checked/unchecked)

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Shadow Properties

• Color
• Softness Gradiation/blurring of shadow edges
• Graininess smoothness of shadow edge

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Depth Map shadows

• Per light, shadows section,
• attribute editor gt Use Depth Map

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Depth map Properties Graininess

• Shadows attribute gt Dmap resolution (on light)
• Higher resolution increases rendering time
• Dmap resolution 256 512

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Depth map properties Softness

• Shadows attribute Dmap Filter Size (on light)
• Tip drop Dmap resolution size, increase filter
  size
• Higher filter size increases rendering time
• Dmap res 128, filter size 3, 5, 7

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Trouble Shooting Dmap

• http//woodall.ncsa.uiuc.edu/dbock/Class/csc187/Le
  cture/LightingAndShadows.html

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Ray-traced shadows

• Per light, shadows section, attribute editor
  Use Ray Trace Shadows
• Window-gtRender Globals, Raytracing quality, turn
  on raytracing

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Ray-traced shadow properties

• Softness/Graininess smoothness of shadow edges
• Shadows attribute Light radius (point, spot) or
  light angle (directional)
• Shadows attribute Shadow Rays (on light)
• Tip time consuming for soft edges w/
  ray-tracing
• Light radius 0.5, Shadow Rays 10 (similar to
  area light)

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Compare

• Depth map shadows create soft edges by blurring
• Ray-traced shadows simulate a more natural
  softening with distance

Point light, depth-mapped shadow
Point light, ray-traced shadow
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Area lights Ray Traced shadows

• Increase number of shadow rays (1, 5, 20)

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Depth Map Shadows
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References

• "Painting with Light" by the late, great John
  Alton

http//www.andrew-whitehurst.net/3point.html
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Credits

• Images and source from
• Jessica Hodgins
• http//warpedspace.org/lightingT/part1.htm
• http//www.andrew-whitehurst.net/3point.html
• http//woodall.ncsa.uiuc.edu/dbock/Class/csc187/

Check out http//www.itchy-animation.co.uk/light
.htm