1. Rendering Particles in the Shafts of Light Presented by Taekyu Shin

2. Clear Day Foggy Day Shaft of Light due to Light Scattering Clear Day Foggy Day Point Source Surface Point Viewer Direct Transmission Scattered (glows)

3. Let’s see what we can improve here

4. Do you see good attenuation? Dobashi [2000], Dobashi [2002] – Shaft of Light

5. Should it be more naturally jittered? Dobashi [2000], Dobashi [2002] – Shaft of Light

6. Another problem (Hoffman 2003) Works only in far view points. No consideration for dense aerosol. – No attenuation. Where are particles? Close view point – challenging

7. My Contribution Good attenuation effect for shafts of light – Result : Later No work for natural attenuation where each particle works as a luminaire. – Bo Sun’s Airlight model(Siggraph 2005) not suited for this. – Our Particle Radiance Method

8. Overview – Ray marching

9. Eye Object

10. Eye Object

11. Eye Object

12. Sum( ) = Eye Object

13. Eye Object

14. =

15. Why this method? This is ‘Multiple Scattering’ – Dense fog exhibit strong multiple light scattering Mark Harris [2001] Can you call it multiple scattering? You are just computing lighting effect from one particle in the unit space. – ‘Just’ one? Most significant particle! (Proof?) This model well suits our goal, too! – The particle effects.  See how particle-based.

16. Hey, but you are still just using one sample? That is not going to work! If based on a well-defined probability function Plausible Grundland [2005]

17. Eye Object

18. Why? Well attenuated based on the distance. – And the distance is based on probability. – Random distance, still overally based on probability. That probability represents the air we are breathing!

19. Each particle as a luminaire again The Sun is not the only light source. – Each particle becomes a light! Eye Object

20. How do we make this model? No over exaggeration of the luminaire intensity Use the surface radiance model from Bo Sun[2005] We modified the model to :

21. Result Real Picture(Left) My Method(Right)

24. Limitation and Future Work No Specularity

25. Questions?