1. Particle Systems in Tree Modeling
CS 658
Mike Jones

2. Objectives Understand particle systems
Describe how particle systems have been used in plant modeling
Compare relative strengths and weaknesses of particle systems in plant modeling given a specific task.

3. Particle Systems Particles are: Particles have:
Individual things
Independent of rendered geometry
Particles have:
Lifespan
Mass, velocity
If rendered, an appearance
Whatever seems handy
Some are independent, some are not.

4. Example: independent particles

5. Example: structured particles
From Reeves and Blau, “Approximate and probabilistic algorithms for shading and rendering structured particle systems” SIGGRAPH 1985

6. Rodkaew For Rodkaew’s particles, what is the… Initial position
Initial velocity
Initial size
Initial color
Initial transparency
Shape
Lifetime
Dynamics (how does the state get updated?)
How are they rendered?
From Rodkaew et al. “An algorithm for generating vein images for realistic modeling of a leaf” in CMM 2002

7. Reeves and Blau For Reeves and Blaus’ particles, what is the…
Initial position
Initial velocity
Initial size
Initial color
Initial transparency
Shape
Lifetime
Dynamics (how does the state get updated?)
How are they rendered?
From Reeves and Blau, “Approximate and probabilistic algorithms for shading and rendering structured particle systems” SIGGRAPH 1985

8. Runions (leaf veins) For Runions particles, what is the…
Initial position
Initial velocity
Initial size
Initial color
Initial transparency
Shape
Lifetime
Dynamics (how does the state get updated?)
How are they rendered?
From Runions et al., “Modeling and visualization of leaf venation patterns” in SIGGRAPH 2005