image-based rendering a brief overview david luebke university of virginia
TRANSCRIPT
Image-Based RenderingA 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 anArray 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