3D Graphics

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3D Graphics
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Module Overview

• Introduction
• 2D, 3D, n dimension graphics
• Stereoscopic 3D
• 3D graphics pipeline
• Basic 3D operations
• Rendering
• 3D graphics tools
• 3D applications
• Benefits and challenges to 3D images

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Module Objectives

• Explain the difference between 2D, 3D and n
  dimensional graphics
• Describe the difference between computer based 3D
  graphics and stereoscopic 3D.
• List and demonstrate 3 basic operations that can
  be performed on a 3D shape.

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Module Objectives - continued

• List and define 3 types of rendering.
• List and define key steps in creating an image
  from a 3D model
• List and describe tools that can be used to
  create 3D graphics
• List and describe applications where 3D graphics
  can be used

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Module Objectives - continued

• Investigate examples of 3D graphics
• Describe the benefits and challenges of using 3D
  images in various applications

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Introduction

• We live in a complex world
• Information can be communicated through images
• Images come in many different formats
• Using the best format can help the viewer
• Understand a concept
• Understand complex relationships
• Gain new perspectives
• Efficiently communicate ideas

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Why 3D Images

• Adds realism to images
• User can manipulate object views for a full 360
  degree perspective
• Adding a third dimension to data can improve
  pattern recognition and increase business
  decision speeds

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Differences Between 2D, 3D ND Graphics
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2D Graphics

• 2 dimensional images are comprised of x and y
  dimensions

2D rectangle
y
y
x
x
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3D Graphics

• 3 dimensional images include x and y dimensions
  as well as a z dimension

3D cube
z
y
y
z
x
x
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N Dimension Graphics

• Images can be created beyond 3 dimensions.
  Generally used in math and sciences.

6-dimensional Calabi-Yau manifold
http//en.wikipedia.org/wiki/ImageCalabi-Yau.png
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Stereoscopic 3D Graphics
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How Stereoscopic 3D Works

• Binocular vision
• Eyes spaced about 2 apart
• Two images must be projected on a screen

Stereogram source image
Stereo image anaglyphed for red (left eye) and
cyan (right eye) filters
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How Stereoscopic 3D Works

• The red/blue glasses implementation require 2
  projected images one red, one blue
• Glasses block one image for each eye for 3D
  effect
• Only works for black and white film

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How Stereoscopic 3D Works

• Polarized glasses work with color film
• Two different images projected on a screen
• Each lens has a different polarization

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3D Computer Graphics
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3D Computer Graphics

• 3D computer graphics are rendered on a computer
  display dont need 3D glasses
• 3D images are created by drawing in a 3 axis
  environment
• Texture, lighting and shading add realism
• Translation and scaling create a realistic
  experience for the viewer when manipulating
  objects or moving through the 3D world

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The 3D Graphics Pipeline
Modeling Transformation
Orientation and arrangement of objects in 3D world
Lighting
Objects and scene is lit based on light source
locations
Viewing Transformation
Create the 3D scene from the camera point of
view
Projection Transformation
Transform 3D scene to 2D
Clipping
Discard unnecessary objects that fall outside the
camera's view
Rasterization
Convert image into pixels
Assign colors to each pixel
Texturing
Display images or scene onto a computer display
Display
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3 Basic 3D Graphics Operations

• Translation
• Rotation
• Scale

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Translation

• When you move a 3D object in one of 3
  dimensions(x, y, z) you are performing translation

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Rotation

• When an object is spun on its axis, an object is
  rotated

A
A
A
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Scale

• Scaling changes the number of pixels in an image,
  in other words, make it larger or smaller.

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3D Graphics Creation

• Modeling
• Scene Layout
• Rendering

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Modeling

• Modeling is the task associated with creating and
  shaping individual objects that will be used in a
  scene
• May also specify materials (textures, types of
  reflections)
• Describe object physical behavior

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Modeling

• Complex shapes are built from primitives such as
  triangles or polygons.

Triangle
Polygons
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Modeling
Individual objects are created and then
assembled into final image
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Scene Layout

• Scene layout requires positioning objects and
  lighting for desired effect.
• Lighting can enhance the visual quality of the
  scene and create different moods.

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Rendering

• Ray Tracing
• Radiosity
• Shading
• Texture

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Ray Tracing

• Ray tracing is a mathematical algorithm that
• Plots the path of light from the viewers
  perspective onto an image
• Can represent reflective and refractive
  properties of light

http//www.tjhsst.edu/dhyatt/superap/povray.html
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Radiosity

• Illumination algorithm that models multiple light
  reflections, resulting in a softer image

Radiosity Factory   http//www.graphics.cornell.ed
u/online/research/
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Shading

• Shading results when the color of an object is
  adjusted to simulate light angles and distance
  from light sources.

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Texture

• Add detail to the surface of a 3-D shape

A sphere without bump mapping
The bump map that is applied to the image.
This sphere is geometrically the same as the
first, but has a bump map applied. This changes
how it reacts to shading, giving it the
appearance of a bumpy texture resembling that of
an orange.
http//en.wikipedia.org/wiki/Bump_mapping
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Putting it all Together
Model
Texture
Shading
D
V
L
Scene Layout
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3D Graphics Pipeline - revisited
Modeling Transformation
Orientation and arrangement of objects in 3D world
Lighting
Objects and scene is lit based on light source
locations
Viewing Transformation
Create the 3D scene from the camera point of
view
Projection Transformation
Transform 3D scene to 2D
Clipping
Discard unnecessary objects that fall outside the
camera's view
Rasterization
Convert image into pixels
Assign colors to each pixel
Texturing
Display images or scene onto a computer display
Display
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3D Graphics Tools

• 3D designers use powerful software tools to
  create the images we see in games, movies and
  other applications. The tools include
• Maya
• 3ds Max
• Lightwave
• Softimage
• Sketchup

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Autodesk - Maya
Leading animation program Feature rich High
learning curve Used by many movie studios
http//usa.autodesk.com
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Autodesk - 3ds Max
Popular animation program used by game
industry Also popular with architects
http//usa.autodesk.com
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NewTek - Lightwave
Easy to learn Not as feature rich as other
packages Popular in film and broadcast industry
http//www.newtek.com
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Avid - Softimage
Animation software Direct competitor to Maya
http//www.softimage.com
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Google - Sketchup
3D Modeling software Easy to learn Free
http//www.sketchup.com
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3D Graphics Applications

• Games
• Entertainment
• Computer Assisted Drafting (CAD)
• Medicine
• Security
• Commerce

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Games

• Most recognizable 3D application
• Requires a number of types of programmers
• Graphics
• Physics
• Sound
• Artificial Intelligence (AI)
• User Interface (UI)

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Entertainment

• Animated movies are a popular form of 3D
  entertainment
• Combines movement with 3D graphics
• Movement can be achieved through motion capture
  or avars
• Motion capture actual person or object performs
  movements with markers tracked by a video camera
• Avars- a computer variable that controls object
  movement

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Computer Assisted Drafting - CAD
Tools used by engineers and designers to assist
in design and documentation of new products
Typical product design flow
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Medicine
Nuclear Medicine Viewer
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Security
3D graphic security tool that can help computer
system administrators identify weaknesses in
network security.
http//blog.tenablesecurity.com/2006/07/3d_tool_sc
reens.html
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Commerce

• Real Estate
• Business Intelligence
• E-retail
• Maintenance, Training, Documentation

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Real Estate
3D graphics can be used by a a user to view a
specific location in 3D. Note that the tool
displayed here permits the user to navigate
through a city in 3D but also has a 2D map
displayed as a reference.
http//www.geosimcities.com/sol_RealEstate.htm
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Business Intelligence
Business Intelligence is the collection of data,
processed into information that managers can use
to make business decisions. Displaying data in 3D
helps decision makers gain insight into complex
relationships.
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E-Retail
http//www.virtualshowrooms.co.za
http//www.technicon.com/products_demos.htmlcf
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Maintenance, Training, Documentation
3D graphical application applied to a practical
application of airplane maintenance, training and
documentation
http//www.parallelgraphics.com
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Standards

• VRML97 original 3D standard that has been
  superseded by X3D. VRML97 is supported by X3D
• X3D open standard based on XML
• Xj3D open source toolkit that support X3D that
  can be used by software developers
• H-Anim Humanoid Animation standard used in
  applying animation to virtual human like figures

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3D Graphics Benefits

• Adds realism
• 3D images can help simplify complexity when
  displaying graphical relations
• User can manipulate object views for a full 360
  degree perspective
• Adding a third dimension to data can improve
  pattern recognition and increase business
  decision speeds

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3D Graphics Challenges

• Requires specialized skills to develop 3D
  applications
• Requires higher performance computer hardware
• Web adoption has been slow, no mainstream
  applications

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Summary

• 3D graphics used extensively in games and
  entertainment
• Industrial 3D graphics applications of CAD
  prevalent
• Some use of 3D in Business Intelligence and
  e-commerce.
• Poised for expansion