Papers by Phillippe Reffye
2009 Third International Symposium on Plant Growth Modeling, Simulation, Visualization and Applications, 2009
The objective of this paper is to study forest growth simulation based on functional-structural m... more The objective of this paper is to study forest growth simulation based on functional-structural modelling and its potentials for forestry applications. The GreenLab model is used for this purpose owing to its computational performances, its calibration capacity on real plants and its extension to the stand level, by taking into account the competition between neighbouring plants and the interactions with the environment. We first propose a software design: • to manage the composition of forest scenes, • to simulate their growth based on parallel computing of individual trees with the GreenLab model, • to get the realistic and real-time 3D rendering of the simulation results. We then detail a test case to illustrate the potentialities of this new tool. Mono-specific stands of poplars and pines are simulated. We analyze the computation performances and illustrate the simulation results with 3D outputs. A very classical application in forest management, stand thinning, is also tested. Our tool provides new insights thanks to the detailed architectures of trees resulting from the functionalstructural model.
Plant models faithful to botanical structure and development
ACM SIGGRAPH Computer Graphics, 1988
Some very impressive results have been obtained in the past few years in plants and trees image s... more Some very impressive results have been obtained in the past few years in plants and trees image synthesis. Some algorithms are largely based on the irregularity and fuzziness of the objects, and use fractals, graftals or particle systems. Others focus on the branching pattern of the trees with emphasis on morphology. Our concern here is the faithfulness of the models to the botanical nature of trees and plants. We present a model which integrates botanical knowledge of the architecture of the trees: how they grow, how they occupy space, where and how leaves, flowers or fruits are located, etc. The very first interest of the model we propose is its great richness: the same procedural methods can produce "plants" as different as weeping willows, fir trees, cedar trees, frangipani trees, poplars, pine trees, wild cherry trees, herbs, etc. Another very important benefit one can derive from the model is the integration of time which enables viewing the aging of a tree (possibil...
La simulation de l'architecture des arbres et son rôle potentiel dans la conception et la gestion des paysages urbains
Revue Forestière Française, 1989
Les recherches effectuees depuis une quinzaine d'annees sur l'architecture et la dynamiqu... more Les recherches effectuees depuis une quinzaine d'annees sur l'architecture et la dynamique de croissance des arbres permettent de decrire leur developpement de la germination jusqu'a la mort. En retracant l'ensemble des formes que l'organisme vegetal presente au cours de son developpement, elles ont conduit a degager les principales lois qui president a leur croissance et ont contribue a la creation d'un logiciel capable de simuler le developpement de l'arbre dans le temps et l'espace. L'objet de cet article est de faire une presentation d'ensemble de ces travaux en insistant sur l'interet potentiel de l'outil informatique dans la conception et la gestion de l'espace urbain
[Application of three-dimensional computer graphics in oncology]
Bulletin de l'Académie nationale de médecine
Accurate 3D tumoral volume evaluation is now possible through the combined use and progress of co... more Accurate 3D tumoral volume evaluation is now possible through the combined use and progress of computer graphics technics (3D reconstruction and visualization) and medical imagery (helicoidal TDM scanner). Specific organ and pathology oriented softwares can help answer rapidly to problems posed by oncologic praticians. A new decision support for diagnosis, therapy and follow-up is emerging. First results in liver tumors and hepatic regeneration macroscopic biometrics are presented. Tumoral or organ volumic index will be usable in the follow-up. TNM staging, external conformal radiotherapy for prostatic or brain tumors, drugs cytolytic effects evaluation will take great advantage of these technologies. 3D visualization and matching CT and MRI imagery can help computed assisted surgery.
Simulation of the Growth of Plants — Modeling of Metamorphosis and Spatial Interactions in the Architecture and Development of Plants —
Cyberworlds, 1998
ABSTRACT In the past, numerous techniques have been used in the representation of plants. The Pla... more ABSTRACT In the past, numerous techniques have been used in the representation of plants. The Plants Modeling Unit of CIRAD developed an original method of plant growth simulation based on botanical notions of plant architecture. But in simulating metamorphosis, the notion of a reference axis which shows all the stages of differenciation in a branch throughout its growth is needed. Also, if we consider the simultaneity of biological events which characterize a plant's functioning, we can study the environmental (nutrition and precipitation needs) and spatial (crowding, light interception) interactions. The reference axis is structured like a finite automaton and the discrete events simulation (schedular) is used for the parralel simulation of growth.
Modélisation et stimulation de l'architecture de l'hévéa= Modelisation and simulation of rubber tree architecture
Modelization and simulation of hevea structure
Stochastic modelling for cotton growth and architecture. 1. Main stems and primary fruiting branches
Modelling the growth of plants
Modelisation et simulation de la croissance et de l'architecture du cafeier
Synthese des travaux effectues en modelisation sur l'architecture du cafeier Robusta (clones ... more Synthese des travaux effectues en modelisation sur l'architecture du cafeier Robusta (clones 182, 126 et 197) dans les plantations de l'IRCC en Cote d'Ivoire entre 1974 et 1980. Ils ont abouti a une theorie generale de la modelisation de la croissance des plantes : elle permet de mesurer et de controler le developpement d'une plante dans son environnement. On utilise le modele stochastique, base sur le fonctionnement aleatoire des meristemes de la plante. Par rapport au modele cinetique il permet a partir des donnees de terrain de calculer les probabilites d'etat des meristemes (ramification, croissance, mortalite) et leur evolution au cours du temps. Les programmes de simulation de la croissance et de l'architecture du cafeier permettront a l'agronomie d'optimiser les espacements des plants en champs, la taille des arbres et meme les dates d'intervention pour les differents traitements
Simulation de l'architecture des arbres
L'architecture des arbres est un domaine de recherche au carrefour de plusieurs disciplines s... more L'architecture des arbres est un domaine de recherche au carrefour de plusieurs disciplines scientifiques telles que notamment la botanique, la physiologie, les mathematiques et l'agronomie. Les approches mathematiques de l'architecture sont nombreuses. La methode que nous proposons est fondee sur la prise en consideration des differents etats des meristemes (fonctionnement, pause, mode de ramification). Elle a permis d'etablir un modele unique capable de simuler a l'aide de l'ordinateur les types d'architectures actuellement connus et leur evolution. Le present article montre les possibilites de ce modele et les applications pratiques que l'on peut en attendre. [...]
La modélisation de la croissance des plantes
Un modele de simulation de la croissance des plantes a ete mis au point a partir, d'une part,... more Un modele de simulation de la croissance des plantes a ete mis au point a partir, d'une part, d'observations botaniques sur le terrain et, d'autre part, d'outils mathematiques dans le domaine des probabilites. Ce modele a donne naissance a un logiciel AMAP (Atelier de Modelisation de l'Architecture des Plantes) grâce auquel il est possible de visualiser, sous forme d'images de synthese, toutes les etapes de croissance d'une douzaine de plantes (hevea, bambou, litchi, cafeier, begonia, cotonnier...) en fonction de certains facteurs tels que la densite de peuplement, la quantite et la nature des engrais..
Modélisation et simulation de l'architecture et de la production végétales
National audienc
Controlling the Architectural Geometry of a Plant’s Growth — Application to the Begonia Genus
Creating and Animating the Virtual World, 1992
During growth, a plant makes use of an architecture whose characteristics are continually modifie... more During growth, a plant makes use of an architecture whose characteristics are continually modified with time. The orientation of the axes, the leaves, and the flowers must be dynamically controlled in the creation of realistic 3-D computer graphic animations of the plant development. Practical solutions adapted to botanical principles are proposed in this document. The solutions allow for modification in relation to time, scale, position and orientation of the organs, all of which are calculated from the plant’s architectural fundamentals (the branching, the phyllotaxy, the length of the internodes, etc.)
Modèles mathématiques du développement et de la croissance de l’architecture des plantes. Le cas du modèle GreenLab
Plant architecture development and growth mathematical modeling shows nowadays increasing interes... more Plant architecture development and growth mathematical modeling shows nowadays increasing interests in multiples areas ranging from agronomy to multimedia topics. Plant architecture results from meristems activities, developing axis establishing the plant structure, and from the various organ compartment source-sink relations, regulating their mutual competitions and expansions. Efficient algorithms, computing organ numbers and their associated biomass can be designed, thanks to compact mathematical operators, issued from botanical and agronomic experience and knowledge. The proposed formalism quantifies the biomass dynamics along plant’s life. The model study behavior, held on simple cases illustrates the plasticity of the approach, reflecting various usual crop individuals growth and development strategies. The model open a wide range of studies; its description is nevertheless restricted here to the simple deterministic case, ignoring also growth with development interactions. Ba...
Surgical and Radiologic Anatomy, 1999
A three-dimensional (3-D) computer assisted reconstruction of the biliary tract was performed in ... more A three-dimensional (3-D) computer assisted reconstruction of the biliary tract was performed in human and rat embryos at Carnegie stage 23 to describe and compare the biliary structures and to point out the anatomic relations between the structures of the hepatic pedicle. Light micrograph images from consecutive serial sagittal sections (diameter 7 mm) of one human and 16 rat embryos were directly digitalized with a CCD camera. The serial views were aligned automatically by software. The data were analysed following segmentation and thresholding, allowing automatic reconstruction. The main bile ducts ascended in the mesoderm of the hepatoduodenal ligament. The extrahepatic bile ducts: common bile duct (CD), cystic duct and gallbladder in the human, formed a compound system which could not be shown so clearly in histologic sections. The hepato-pancreatic ampulla was studied as visualised through the duodenum. The course of the CD was like a chicane. The gallbladder diameter and length were similar to those of the CD. Computerassisted reconstruction permitted easy acquisition of the data by direct examination of the sections through the microscope. This method showed the relationships between the different structures of the hepatic pedicle and allowed estimation of the volume of the bile duct. These findings were not obvious in two-dimensional (2-D) views from histologic sections. Each embryonic stage could be rebuilt in 3-D, which could introduce the time as a fourth dimension, fundamental for the study of organogenesis.
Basic concepts of computer plants growth simulation
Journal of Biosciences, 1992
The experimental study of plant growth and architecture requires two consecutive and complementar... more The experimental study of plant growth and architecture requires two consecutive and complementary approaches. The first one is qualitative and botanical. Through this qualitative analysis, it is possible to divide a tree into botanically homogeneous subunits. The second one is quantitative. Modelling of the functioning of meristems based on stochastic processes has been carried out in the Laboratoire de Modelisation of CIRAD (1980-1999) in combination with extensive experimental work on temperate and tropical plants. Calculations involved in the tree simulations from field data are based on the probabilistic Monte Carlo method for the topological part and on analytical geometry for the morphological part. Data, such as length, angles, elasticities, tropism, are necessary for geometric construction of the plant. The growth model, together with the geometric calculations enables a random plant simulation in 3-D according to geometry for the morphological one. Computer graphics methods are then used to visualize the computed plant (perspective, colours, texture, shadows); they require special programs and graphic computers.
A fast algorithm for calculating stem and branch radial growth in a tree
[Modelling and simulation of the growth and architecture of the coffee tree]
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Papers by Phillippe Reffye