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Final Course Slides Online!
The final course notes presented at SIGGRAPH 2001 are now available:
Additional Selections from the SIGGRAPH 2001 Course Notes:
Course Summary:
Using images of real light to illuminate computer-generated scenes
provides new levels of realism and new avenues for creativity. This
course teaches everything from the theory behind the techniques to the
nuts and bolts of using image-based lighting in actual production with
commercially available software. Topics include high-dynamic range
imagery (HDRI), lighting acquisition, illuminating real and synthetic
objects with measurements of real light, global illumination,
real-time techniques, and photoreal compositing.
Expanded Course Statement:
This course will present recently developed techniques for
realistically integrating computer-generated imagery with live-action
photography that use measurements of real-world lighting to illuminate
CG objects. The course will present background material in high
dynanmic range photography, global illumination, and light reflection,
and will describe both the theory and practice of acquiring
measurements of light in the real world and injecting this light into
computer animations. The techniques will be illustrated with detailed
breakdowns of the animations "Rendering with Natural Light" and "Fiat
Lux" and shots from recent feature films. Examples of applying the
techniques using commercial packages such as LightWave 3D will also be
presented. The course will conclude with an overview of techniques to
extend image-based lighting to people and objects in the real world.
Prerequisites:
Participants should have basic knowledge of or experience with
modeling and rendering in a traditional modeling/rendering package, for
example 3D Studio Max, LightWave 3D, Maya, or SoftImage, and be
familiar with basic traditional CG lighting and compositing. No
advanced ray tracing or global illumination knowledge is assumed.
Topics:
This course will cover high-dynamic range photography, lighting
acquisition, image-based lighting and compositing, real-time
techniques, and ongoing research in illuminating real people and
objects with sampled light. Use of the techniques in actual
productions and with particular software packages will be explained.
Additionally, the course will cover the basics of light reflection and
global illumination necessary for understanding the techniques
presented.
Tentative Syllabus:
1:30-2:15pm
- Introduction
- What is image-based lighting?
- How does it differ from traditional techniques?
- An Overview of How Light Works
- What light is and how it is generated
- How light reflects off of (and scatters through) surfaces
- Specular, diffuse, retro-reflection, arbitrary BRDFs
- Measuring BRDFs
- How everything reflects everything else
- Effects and examples of real-world light interreflection
- How environmental illumination determines the appearance of an object
- Global Illumination Overview
- Basics of radiosity techniques
- Basics of Monte-Carlo global illumination techniques
- Introduction to the RADIANCE global illumination package
- How Cameras measure light
- Lenses, Shutters, Apertures, CCD arrays, and ADCs
- Luminance response
- Color response
- Imperfections
- Flare, chromatic abberration, vignetting
- How to compensate for these imperfections
2:15-3:00
 Recovering High Dynamic Range Images (HDRI) from Photographs
 Recording Real-World Illumination
- What to look for in a camera
- Types of mirrored balls
- Acquiring a light probe image using a mirrored ball
- Alternate light probe techniques
- Panoramic camera techniques
- Low-dynamic range techniques
- Real-time light probes
- Rendering synthetic probe images
- Illuminating Synthetic Objects with Real Light
- Mapping a light probe image into a CG environment
- Simulating light from the environment on the object
- Converting light probe images to light source constellations
 Making "Rendering with Natural Light" (SIGGRAPH 98 Electronic Theater)
- Modeling the scene
- Acquiring the light
- Rendering the scene
- Communicating the sense of brightness
- Vignetting
- Defocus and effects thereof
- Motion Blur
- Glare
- Using the custom "pflare" RADIANCE program to produce these effects
- Re-rendering with Natural Light - creating the DVD edition
- Improved sampling of curved surfaces
3:00-3:15 Break
3:15-3:40pm
- Rendering Synthetic Objects into Real Scenes
 Making "Fiat Lux" (SIGGRAPH 99 Electronic Theater)
- Combining Image-Based Lighting with Image-Based Modeling and Rendering
- Creating "illum" light sources for direct lighting
- Integrating animated objects
- Avoiding interframe flickering
- Reflectance property tricks to avoid sparkling
- Inverse global illumination for the floor of St. Peter's
- Distributed rendering
3:40-4:05pm
- Image-Based Lighting with Commercial Renderers and in Commercial Production
- Image-Based Lighting in Lightwave 3D 6.0
- Image-Based Lighting in Standard Ray-Tracers (LightWave 5.5, BMRT)
- Image-Based Lighting with Scanline Rendering
4:05-4:20pm
- Overview of real-time image-based lighting techniques
- Environment Mapping (including history thereof)
- Prefiltering techniques
- What accuracy is lost?
Related papers:
Ned Greene, "Environment Mapping and Other Applications of World Projections"
Gibson and Murta, "Interactive Rendering with Real-World Illumination", EGRW 2000
4:20-5:00pm
- Image-Based Lighting Real Objects and Actors
- Acquiring Reflectance Fields with a Light Stage
- Illuminating reflectance fields
- Real-time image-based lighting of human faces
- Acquiring reflectance fields of objects
- Combining with Environment Matting techniques
- Reflectometry from reflectance fields and surface geometry
Related papers:
Debevec et al, "Acquiring the Reflectance Field of the Human Face", SIGGRAPH 2000
Zongker et al, "Environment Matting", SIGGRAPH 99
5:00pm End
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