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Joshua Smith and Garrick Solberg CSS 552 Topics in Rendering. 3D Anaglyph stereoscopic rendering. What is Stereoscopy?. Adds “depth” to a two dimensional image via stereopsis Two planar images are rendered, one for each eye - PowerPoint PPT Presentation
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3D ANAGLYPH STEREOSCOPIC RENDERING
Joshua Smith and Garrick SolbergCSS 552 Topics in Rendering
What is Stereoscopy?
Adds “depth” to a two dimensional image via stereopsis
Two planar images are rendered, one for each eye
Through some method, such as color filters, the brain is tricked into believing it is seeing one image, resulting in the perception of depth
Human Depth Vision
Our eyes see two slightly different views into the world Ex: look at an object and
close one eye, then switch
The eyes shift and rotate these views onto a point of convergence. Objects closer or farther away than this point creates parallax.
Anaglyph Projection
Image corresponding to the right eye projection is displayed on one color (blue, green, or cyan)
Image corresponding to the left eye is displayed in red
Stereo glasses filter out the image an eye is not supposed to see by matching the color
Parallax
Measuring Positive Parallax
PQ/LR = VQ/VR
VQ/VR = VM/RN= (w – C)/w =1 – C/w
p = D(1 – C/w)
Measuring Negative ParallaxPQ/LR = QV/VR
= QV/(QR-QV)= (QV/QR)/(1 – (QV/QR))
QV/QR = VM/RN= (C-w)/C = 1 – w/C
PQ/LR = p/D =(1-w/C)/(w/C) = C/w -1
p = -D(1 – C/w)
Single Camera Frustrum
Dual Camera Frustrum
Dual Camera Frustrum
FrustrumCalculationDiagram
top = Dnear * tan(θFOVy/2)
bottom = -top
a = raspect * Ctan(θFOVy/2)
Special Considerations
Eye (camera) separationConvergence distanceCamera positionsHigh contrast
Eye Separation
Human eyes are 6.5cm apartLess will loose informationMore will create greater spatial view but harder on eyesImages from :http://www.cafedownloads.com/reviews/r13/3dstereo.html
Convergence
Scale of 1/30 between observer and closes object.
Based off of the space between eyesEquivalent to ≈ 2 meters from a
window Viewing area is both the window and
the horizon.
Convergence – Hyper-StereoCloser than 1/30th Makes the image seem like a model
Image from:http://www.flickriver.com/photos/ur4chun8/3529791785/
Convergence Hypo-StereoFarther than 1/30thEnlarges the image
Image fromhttp://www.flickr.com/photos/adcnj3d/5414231379/in/photostream/
High Contrast
Creates "ghosts" where anaglyphs are too close/strong red and cyan spots
Areas with lots of red or green/blue areas will have little to no information for the corresponding eye
Types of Images
Time sequential Shutters close to match to left and right
images on screen Polarized
Each lens will block light polarized in the opposite direction with two images superimposed
Anaglyph Glasses with two different colored lenses
that corresponds to two images superimposed
Types of Anaglyphs
Type Colors Visible Red – Green Red – Blue Red – Cyan Magenta – Cyan Anachrome Mirachrome Trioscopic Inficolor ColorCode 3D
Monochrome Monochrome Bad reds good greens Better than Red – Cyan Bad reds Bad reds Better colors Fuller colors Almost full color
Cutesy of Wikipedia
Limitations with Anaglyphs Image quality
High contract colors
Limited on what colors are displayed by lens type
Questions?