image-based rendering: 1st wave
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Image-Based Rendering: 1st Wave. Definition : Using images to enhance the realism of 3D graphics Brute Force in Image-Space, L. Williams Texture maps for surface detail Mipmapping (antialiasing) Zbuffers for hidden surfaces Shadow mattes and maps Object tags. - PowerPoint PPT PresentationTRANSCRIPT
NVIDIA Lecture 10 Copyright Pat Hanrahan
Image-Based Rendering: 1st Wave
Definition: Using images to enhance the realism of 3D graphics
Brute Force in Image-Space, L. Williams
Texture maps for surface detail
Mipmapping (antialiasing)
Zbuffers for hidden surfaces
Shadow mattes and maps
Object tags
NVIDIA Lecture 10 Copyright Pat Hanrahan
Image-Based Rendering: 2nd Wave
Represent (model and render) environments without using
traditional geometric representations (polygons)
Examples QuickTimeVR and panoramic image representations Light fields or virtual holograms Color + Range images Coupling viewing and morphing
Advantages Cost independent of scene complexity Imagery from real or virtual scenes Modest computation compared to classical C.G.
NVIDIA Lecture 10 Copyright Pat Hanrahan
Applications
Capture 3D environments
MIT’s ASPEN MovieMap, Cyan’s MYST and RIVEN
Museums, real estate, products, sets, planets
Interactive 3D Graphics and Games Representations of complex environments (lod)
Background environments
Textured portals
3D sprites, billboards and imposters Post rendering warps
Frame interpolation, priority rendering (Talisman)
Latency compentation: HMDs, networked telepresence
Stereo from single RGBZ image
NVIDIA Lecture 10 Copyright Pat Hanrahan
Apple’s QuickTime VR
Outward Inward
NVIDIA Lecture 10 Copyright Pat Hanrahan
History of Panoramas
Robert Barker’s Panorama (1792)
50’ high, 400’ circumference, platform for viewing
Raoul Brimoin-Sanson’s Cineorama (1897)
10 synchronized projectors, 300’ circumference
Disney’s CircleVision
9 35mm projectors
Mirrored panoramic camera
Modern IMAX and OMNIMAX theaters
NVIDIA Lecture 10 Copyright Pat Hanrahan
Panoramic Cameras
Rotating Cameras
Kodak Cirkut
Globuscope
Stationary Cameras
Be Here
NVIDIA Lecture 10 Copyright Pat Hanrahan
Mars Pathfinder Panorama
NVIDIA Lecture 10 Copyright Pat Hanrahan
Creating a Cylindrical Panorama
From www.quicktimevr.apple.com
NVIDIA Lecture 10 Copyright Pat Hanrahan
Stitching
Prewarping
Lens Distortion, Radiometry,Cylindrical projection
Image Registration
Feature alignment,Pixel difference minimization, Fourier correlation
Global Alignment
Gap closingMutual image aligment
Compositing
Blending,Nearest NeighborExample courtesy James Davis
NVIDIA Lecture 10 Copyright Pat Hanrahan
Commercial Products
QuickTime VR, LivePicture, IBM (Panoramix)
VideoBrush
IPIX (PhotoBubbles), Be Here, etc.
NVIDIA Lecture 10 Copyright Pat Hanrahan
Future Directions
Geometry + panoramas
Hot spots
Hierarchical panoramas
Stereo / depth-mapped panoramas
Video panoramas
NVIDIA Lecture 10 Copyright Pat Hanrahan
Light Field
Key Ideas:
4D function
- Valid outside convex hull
2D slice = image
- Insert to create
- Extract to display
Inward or outward
NVIDIA Lecture 10 Copyright Pat Hanrahan
Two Plane Parametrization
ObjectFocal plane (st)
Camera plane (uv)
NVIDIA Lecture 10 Copyright Pat Hanrahan
NVIDIA Lecture 10 Copyright Pat Hanrahan
Reconstruction
NVIDIA Lecture 10 Copyright Pat Hanrahan
Original prototype gantry
Issues: focal plane, aperture, support, lighting
NVIDIA Lecture 10 Copyright Pat Hanrahan
New light field gantry
Applications:
digitizing light fields
measuring BRDFs
range scanning
Designed by
Marc Levoy et al.
NVIDIA Lecture 10 Copyright Pat Hanrahan
Light Field Camera
prototype(32 z 2)
long-term goal(32 z 32)
light field
imaging chip
compression chip
Concept: Pat Hanrahan Mark Horowitz Marc Levoy
NVIDIA Lecture 10 Copyright Pat Hanrahan
Dayton Taylor’s Multiple Camera Rig