CS184 Section 4
Environment Maps and Image-Based Lighting

Brandon Wang
February 19, 2013
Material adapted from James O'Brien, Fu-Chung Huang, Ravi Ramamoorthi, and Carlo Sequin.

Logistics

• AS2 out soon.™

Today

• Clarifications on anything
• OBJ Files
• Environment Maps
• Image-based Lighting

Clarifications on Anything

• Phong Illumination Model
• Transformation Spaces
• Rodrigues Rotation Formula
• Ray Tracing

OBJ Files

These are quite simple.

Environment Maps

Your environment is an image.

Environment Maps

Environment Maps

Perfect Reflection (Mirror)

When your reflected ray misses all objects in your scene, use the environment map!

Everything else..

Distributed Ray Tracing

Everything else..

HDR

You will probably want to use HDR images for this...

Grabbing the images

Paul Debevec (Berkeley alum)

Precomputed Radiance Transfer

Now think of every pixel as a light...

Add lights linearly...

Light Stages

Video

Another Video

Precomputed Radiance Transfer Compression

Spherical Harmonics

Haar Wavelets

Etc