- I’m out of town from this afternoon through Friday
- “Class” will be on-line exercise in designing next ray tracer
- What coordinate system do you do shading and shadow calculations in?
- World coordinate system
- Transforming points and most vectors between coordinate systems just requires multiplying by the canonical-to-world or world-to-canonical transformation matrix
- But this isn’t true of normal vectors!
- So derive the right transformation for normals:
- If points transform by T, normals have to transpose by (T-1)T
- Ray tracer 3
- Handout
- Online part re designing ray tracer starts now