Particle Systems in Tree Modeling CS 658 Mike Jones

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.

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.

Example: independent particles

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

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

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

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