Image-Based Rendering A Brief Overview David Luebke University of Virginia

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Image-Based Rendering A Brief Overview David Luebke University of Virginia

Context  Bad: I don’t have assignment #1 graded – Worse: won’t be graded this week at all  Next major topic: programming the vertex and fragment pipelines – Big topic, several lectures – Assignment #3  But first, next couple of lectures will be “culture” topics – Image-based rendering – Parallel graphics

Image-Based Rendering  You’ve been learning how to turn geometric models into images – Specifically, images of compelling 3D objects and worlds 

Image-based rendering

: a relatively new field of computer graphics devoted to making images from images  Ex: Quicktime VR

Images with depth  Quicktime VR is really just a 2D panoramic photograph – Spin around, zoom in and out  But what if we could assign depth to parts of the image?

 Ex: Tour Into the Picture

Tour Into the Picture  Software for: – Selecting parts of an image – Assigning a vanishing point for depth of background objects – Assigning depth to foreground objects – “Painting in” behind objects

Depth per pixel  What if we could assign an exact depth to every pixel?

 Ex: MIT Image-Based Editing system

Depth per pixel continued  What if we had a “camera” that

automatically

pixel?

acquired depth at every  Ex: deltasphere  Ex: Monticello project

General image-based rendering  Can we do anything if we don’t have depth at every pixel?

– Intuitively, if we had

enough

images we should be able to reconstruct new images from novel viewpoints – Even without depth information – This is the problem of pure image-based rendering

A 4-D Light Field

Creating Light Fields

Light Field as an Array of Images

Fast Rendering of Light Fields

Use Gouraud Shading Hardware!

Light Field Rendering  Demo of Stanford viewer and light fields…

View-Dependent Rendering  Spectrum of rendering techniques from pure IBR to pure geometry  Points in this space: – Pure IBR: light field/lumigraph – Depth-per-pixel approaches  Another point: view-based rendering – Slides at: http://graphics.stanford.edu/~kapu/vbr/webslides/index.html

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