1. Image-Based Modeling, Rendering, and Lighting
By Vanessa Newey

2. Introduction Traditional 3D Modeling and Rendering
Image-Based Modeling, Rendering, and Lighting
Applications
Available Tools
Summary

3. Traditional 3D Modeling and Rendering

4. Traditional 3D Modeling and Rendering Developments
Hidden Surface Removal Algorithms
Shading Algorithms
Shadow Calculation
Displaying Curved Surfaces
Ray tracing and Radiosity
Powerful Modeling Tools

5. 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

6. 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

7. Image-based Modeling and Rendering
Create 3D models from one or more images
Re-render creating new views
Easier to model scenes photorealistically

8. Image-based Modeling, Rendering

9. Computer Graphics- Computer Vision

10. Image-based Modeling
Images (photographs, renderings) are used to determine:
Scene Appearance
Scene Geometry
Lighting
Reflectance Characterisics
Kinematic Properties

11. 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

12. 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.

13. Example

14. Example Video

15. Stereo Image Capture Rig

16. Applications VR worlds and Games Creating terrain from Air-Photos
Construction of virtual scenes
Creating terrain from Air-Photos
Images and Video on the WWW
Video compression, summarisation, skimming, indexing and selective retrieval

17. Tools REALVIZ ImageModeler ERDAS IMAGINE OrthoMax ERDAS Stereo Analyst
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

18. REALVIZ ImageModeler 1 Start the project
Take from 2 to more photos from your scene or object.
No other information is required
Start the project
Take from 2 to more photos from your scene or object, no information from the set or camera, nor special track marks are required

19. REALVIZ ImageModeler 2 Calibrate cameras
Add common markers to each photographs
ImageModeler automatically calibrates your cameras
Calibrate cameras

20. Model your scene or object using standard polygon modeling tools:
REALVIZ ImageModeler 3
Model your scene or object using standard polygon modeling tools:
Create a model
Model your scene or object using standard polygon modeling tools:
extrude, path extrude, bevel tool, split polygon, mirror object, merge objects, snap and pin primitive tools

21. Capture textures per face, or unfolded single textures
REALVIZ ImageModeler 4
Capture textures per face, or unfolded single textures
Texture a model

22. Export camera, objects and textures to your favorite 3D application
REALVIZ ImageModeler 5
Export camera, objects and textures to your favorite 3D application
Export a model

23. ERDAS Stereo Analyst

24. 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.

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

26. Sources http://i31www.ira.uka.de/~oel/ibmr-focus/
3D modeling from images tutorial
ERDAS Products
REALVIZ ImageModeller