==== notes ====
notes for research gathering on 2008-11-28 at FoAM
related >>  [[project groworld]]

====what tools can we use to simulate plants?====
  - form -> (...)
  - function -> more involved

====L-Systems====

"The power of L systems goes beyond their capability to generate realistic images of plants [...] they also provide a model of their operation, including processes such as tropisms, abscission, signal propagation, or watering."

--Roberto S. Ferrero

There is a number of applications in which L systems plays an important role as a biological model:
  - structural models of trees integrated in more complex forest ecosystem simulations,
  - identifying plant response to insect attack,
  - design of new varieties of plants,
  - reconstruction of extinct plant species,
  - crop yield prediction,
  - classification of branching patterns in inflorescences,
  - simulation of fungal growth, or
  - computer aided learning for farm managers."

via. Roberto S. Ferrero

Following the structure of "algorithmic beauty of plants"...

====DOL-systems ====
  * deterministic & context free (simple) l-systems
====Stochastic L-systems ====
  * variations & randomness

==== Context-sensitive L-systems ====
  * symbol replacement dep. on context, or previous states
  * can be used to model signal propogation 

==== Parametric L-systems ====
  * elements can be parameterised, eg. segment lengths
  * continous development, motion, growth or diffusion 
==== Developmental models (ABOP 3.1 ->)====
  * L-systems provide good structural models, how can we model growth and changes over time?
  * multi-level models
    * partial l-system (structural - non deterministic)
    * l-system schemata (control mechanisms, resolve n.d., temporal aspects)
    * complete l-system (geometric info, growth rates/branching/appearance)
  * compound flowering structures (inflorescences)
  * Phyllotaxis. In order to describe the pattern of florets (or seeds) in a sunflower head, Vogel proposed the formula φ=n∗137.5◦, r=c√n {cf. ABOP 4.1}
  * surface models  (ABOP 5)
    * the shape as well as size of plant organs may change over time
    * leaf types

====animation (ABOP 6)====
  * The original formalism of L-systems provides a model of development that is discrete both in time and space. 
    * the model states are known only at specific time intervals.
    *  spatial organisation is finite
    * Parametric L-systems remove the limits imposed by discrete spatial representation 
       * assign continuous attributes to model components
       * model states are still known only in discrete time intervals. 
==== Timed DOL systems====
   * expression of production rules is still discrete, yet each cell has its own 'lifetime' as specified in the production rule
   * symbols represent cells that elongate during their lifetime and divide upon reaching terminal age.
   * effect of aging, and gradual development can be modeled
   * 'young' cell can be replaced by mature form -> fruits

==== open L-systems====
  * "Visual Models of Plants Interacting with Their Environment"  Radomír Mech and Przemyslaw Prusinkiewicz
  * [x.ref]

====reaction diffusion systems====
  *  what advantages/disadvantages over l-systyems? 
  * why another abstraction?

====can we model plants interacting with each other and their environment?====
  * benefits
  * tradeoffs

====demos====
  * http://www.blprnt.com/processing/cherrytree/
  * http://www.blprnt.com/processing/birchtree/
  * karl sims - panspermia (1990) http://www.youtube.com/watch?v=AgeuRukfZLE from ~1:00 onward

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====Further====
  * http://openalea.gforge.inria.fr/
  * https://team.inria.fr/virtualplants/software/