Omnidirectional Rendering

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Omnidirectional Rendering

• Jiesang Song
• Stephanie Weirich

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Motivation

• Rendering is neat
• Many video games strive to immerse the player in
  an imaginary world.
• Rendering is slow
• Complexity is based upon the number of objects in
  the scene, as well as the number of pixels in the
  output.

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Quake screen shot
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Riven screen shot
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Inspiration

• Columbia Omnicamera - Teleconferencing

• Quicktime VR - Panoramic Imaging

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(No Transcript)
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Methodology

• Render complex scenes ahead of time in an
  Intermediate Image
• Compute several perspective views from that one
  image

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Methodology
declare Glas2 sor 12, lt.517241379,
-.132625995gt lt.249336870, 0.000000gt
lt.068965517, .031830239gt lt.021220159,
.050397878gt lt.238726790, .602122016gt
lt.249336870, .721485411gt lt.233421751,
.864721485gt lt.167108753, 1.000000000gt
lt.084880637, 1.055702918gt open
POV Source
Hemisperical view
Perspective view
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Parabolic Mirror
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Generalization

• Parabolic mirror defines a function between the
  angle of elevation, ?, of a ray and the radial
  distance, r, of its location in the image.

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Generalization

• We dont need to follow physical laws
• We can use (almost) any function of q we wish!
• Parabolic mirror model shows us how

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Generalization (Cont)
Different functions allow us to adjust the
resolution of parts of the image Fisheye lens - r
is linear in q Another function might allow us
to have more resolution near the horizon.
Parabolic Mirror
Fisheye lens
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Implementation Overview

• Initialize windows application
• Initialize DirectDraw Surface in Video memory
• Read in .PPM files
• Run conversion algorithm
• Initialize Device Independent Bitmap (DIB)
• Stretch and copy Bitmap into DirectDraw Surface
• Enter message processing loop

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Interface

• Move mouse to pan image
• Use left/right mouse buttons to zoom in and out
  (limited depth)

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Performance

• About 1 3 seconds to generate new 640480 or
  320 240 images on Intel Pentium 200 MHz running
  Win95
• About 5 9 seconds for 1024 768 images but
  takes longer to initialize
• Room for optimization