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By Vanessa Newey

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Introduction

Traditional 3D Modeling and Rendering

Image-Based Modeling, Rendering, and Lighting

Applications Available Tools Summary

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Traditional 3D Modeling and Rendering

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Traditional 3D Modeling and Rendering Developments

Hidden Surface Removal Algorithms

Shading Algorithms Shadow Calculation Displaying Curved Surfaces Ray tracing and Radiosity Powerful Modeling Tools

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Limitations of Traditional 3D Modeling and Rendering

Possible to Visualise Complex 3D Models in Real Time

BUT… Creating these 3D models requires

Expertise and Time. Rendering is Slow

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Motivation for Image-based Modeling and Rendering

Demand for more complex, realistic models

Traditional methods slow and costly Many virtual objects based on real

objects Advantageous to model directly

from real objects

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Image-based Modeling and Rendering

Create 3D models from one or more images

Re-render creating new views Easier to model scenes

photorealistically

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Image-based Modeling, Rendering

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Computer Graphics- Computer Vision

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Image-based Modeling

Images (photographs, renderings) are used to determine:

Scene Appearance Scene Geometry Lighting Reflectance Characterisics Kinematic Properties

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Image-based Rendering

Appearance in available views is used to determine appearance in novel views

Not necessary to perform full illumination computations

Rendering is faster

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Image-based Lighting

Able to Create a Light-based Model from the images

For each part of the local scene, we know its irradiance

Allows us to combine real and synthetic graphics with consistent illumination, using images as light sources.

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Example

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Example Video

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Stereo Image Capture Rig

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Applications

VR worlds and Games Construction of virtual scenes

Creating terrain from Air-Photos Images and Video on the WWW

Video compression, summarisation, skimming, indexing and selective retrieval

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Tools REALVIZ ImageModeler

http://www.realviz.com/

ERDAS IMAGINE OrthoMax Automated DEM extraction

ERDAS Stereo Analyst Provides tools for collection, interpretation

and visualisation of 3D geographic information from stereo imagery

3Q Qlonerator Series http://www.3q.com/offerings_tech.htm

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REALVIZ ImageModeler 1

Take from 2 to more photos from your scene or object.

No other information is required

Start the project

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REALVIZ ImageModeler 2

Add common markers to each photographs ImageModeler automatically calibrates your cameras

Calibrate cameras

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REALVIZ ImageModeler 3

Model your scene or object using standard polygon modeling tools: Create a model

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REALVIZ ImageModeler 4

Capture textures per face, or unfolded single textures

Texture a model

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REALVIZ ImageModeler 5

Export camera, objects and textures to your favorite 3D application

Export a model

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ERDAS Stereo Analyst

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Challenges

Automatic scene segmentation Complex scenes eg. forests Non-static scenes Inaccuracies in source photos Real imagery/computer vision problems

Camera pose hard to get Depth even harder to get

Data Size may be huge Changes Difficult

lights, geometry, etc.

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Summary

Overall… exciting developments and much more potential for Image-based modeling, rendering and lighting.

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Sources http://i31www.ira.uka.de/~oel/ibmr-focus/ http://www.debevec.org/IBMR99/ http://www.cs.berkeley.edu/~debevec/IBMR http://research.microsoft.com/~szeliski/IBMR98/web/sld001.htm http://www.esat.kuleuven.ac.be/~pollefey/

3D modeling from images tutorial http://www.esat.kuleuven.ac.be/~pollefey/SMILE2/tutorial.html

ERDAS Products http://www2.erdas.com/supportsite/apps_gallery/flume_bed/flume_bed.htm http://www2.erdas.com/supportsite/apps_gallery/videography/videography_raw.htm http://www.erdas.com/software/ProductModules.asp?SubGroupID=513&GroupID=1

REALVIZ ImageModeller http://www.realviz.com http://www.realviz.com/products/stepbystep.php?product=im

http://www.debevec.org/Campanile/ http://www.sciencedirect.com/science?_ob=ArticleURL&_aset=A-WA-A-AZ-MsSAYVW-UUA-AUWEYAVWAY-

ZWCEYCVAE-AZ-U&_rdoc=8&_fmt=summary&_udi=B6V08-40J1J3P-1&_coverDate=08%2F31%2F2000&_cdi=5640&_orig=search&_st=13&_sort=d&_acct=C000028338&_version=1&_urlVersion=0&_userid=554534&md5=d41937e1648632dae517f65375553a62

http://www.cs.yorku.ca/~vgrlab/projects/imgrender.html