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 acquired depth at every pixel?
 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