L-system Grammar Research Articles

Three- dimensional modeling and visualization of rice root system based on the improved dual-scale automaton and L-system

• The 3D Visualization growth modeling of rice roots was proposed. • The improved dual-scale automaton described the root growth process. • The growth model and morphological structure model were transformed into L-system. • Ten phenotypic traits were quantified. • The relationship between root structure and functional traits was aided analyzed. In agronomy sciences and researches, root system architecture (RSA) of Oryza sativa L. (rice) is often used to reflect the spatial configuration of rice roots. But, because soil has its own opacity, the cognition and expression of the spatial morphology and structure of rice roots have become the bottleneck in the in-depth study. The three-dimensional (3D) modeling and visualization can be used to help further study and recognize the morphological, structural and functional traits of rice roots. To clarify the rules governing the structure and distribution of the rice root system, and so to understand the relationship between RSA and the functionality of rice roots, a method combined the improved dual-scale automaton with Lindenmayer-system (L-system) for the three-dimensional modeling and visualization of the rice root system is hereby proposed. The basic parameters of the rice root growth were firstly measured by the destructive detection, and various appropriate growth functions were selected according to the rice root growth rule and development so as to control the rice root growth rate in the modeling. In the dual-scale automaton modeling, the identifiers of micro-states and macro-states were redefined with numbers and characters, and hence the improved dual-scale automaton model was used to describe the growth process of rice roots, which was then combined with L-system grammar. According to the morphological structure characteristics of the rice root growth, the direction and radius of the rice root growth were constrained, and a single three-dimensional morphological model was thus constructed. Then, the visualization of the rice root growth was realized by MATLAB. By calculating the total rice root length, total rice root surface area, total rice root volume, maximum rice root width, maximum rice root depth and other indicators of the model, as well as analyzing and comparing the experimental measurement data, it was finally found that the average accuracy of the simulation of the total rice root length, total rice root surface area and total rice root volume was 94.27%, 93.68% and 92.35%, respectively. Besides, the maximum rice root width and maximum rice root depth had strong correlation with the corresponding measured data. So, the results showed that the model had good simulation effects on the rice morphological structure. Again, based on this, the relationship between the rice root structure and its functions was further analyzed by quantifying the structural parameters such as the rice root length fraction, solidity, convex hull volume, rice root volume density and rice root surface area density, etc. This model laid a foundation for the coupling of both the morphological structure model of the rice root growth as well as the model of physiological and ecological factors of next stage, hoping to provide a reference for the 3D modeling and visualization research of the root growth of other crops.

A Modular Generative Approach for Realistic River Deltas: When L-Systems and cGANs Meet

Procedural terrain generation aims to create topographically coherent landscapes with realistic terrain features. Realistic landscapes of our blue planet are not complete without river deltas; however, there is an insufficient advancement in the generation of landscapes with this terrain feature. Therefore, this paper presents a modular approach to generate landscapes focused on the river deltas features. The modular proposal initially creates skeletons of deltas using a stochastic L-system grammar; we include the guidelines for the rules design. In the first module, we propose three L-systems that automatically create delta skeletons using these guidelines. The second module constructs the coastline and the sedimentary lands for the delta skeleton. Finally, the third module uses conditional generative adversarial networks (cGANs) to create the corresponding digital elevation models (DEMs) and land surface images. The evaluation of our proposal includes visual comparisons, and image quality metrics: the Frechet Inception Distance (FID), and the Naturalness Image Quality Evaluator (NIQE). The proposed modular integration generates realistic deltas with enough variability to outperform related work.

Rhythmic Recursion? Human Sensitivity to a Lindenmayer Grammar with Self-similar Structure in a Musical Task

Processing of recursion has been proposed as the foundation of human linguistic ability. Yet this ability may be shared with other domains, such as the musical or rhythmic domain. Lindenmayer grammars (L-systems) have been proposed as a recursive grammar for use in artificial grammar experiments to test recursive processing abilities, and previous work had shown that participants are able to learn such a grammar using linguistic stimuli (syllables). In the present work, we used two experimental paradigms (a yes/no task and a two-alternative forced choice) to test whether adult participants are able to learn a recursive Lindenmayer grammar composed of drum sounds. After a brief exposure phase, we found that participants at the group level were sensitive to the exposure grammar and capable of distinguishing the grammatical and ungrammatical test strings above chance level in both tasks. While we found evidence of participants’ sensitivity to a very complex L-system grammar in a non-linguistic, potentially musical domain, the results were not robust. We discuss the discrepancy within our results and with the previous literature using L-systems in the linguistic domain. Furthermore, we propose directions for future music cognition research using L-system grammars.

Preliminary Experiments on Human Sensitivity to Rhythmic Structure in a Grammar with Recursive Self-Similarity.

Preliminary Experiments on Human Sensitivity to Rhythmic Structure in a Grammar with Recursive Self-Similarity.

Apporach Geometry/Image for Rendering Forest in Real Time

Representation and visualization of a forest in real time is a difficult task, the main difficulty of this problem is the complexity, forest scenes contain a very large quantity of small details difficult to model, expensive to make and require very large amount of memory. The goal of our research is to present an approach for modeling and rendering of natural objects that must be used to bypass the obstacle of the geometric complexity and provide simple model for the creation of natural structures. Our work focuses on trees that represent the forest. To simplify the complexity of the scene, the trees from a distance are represented by billboards (single, cross, ...) for tree views near, we propose an hybrid model between billboards and L-systems, where we separate the tree into two separate trunks and branches are represented by an L-system grammar and leaves are represented by billboards, this increases the realism of nearly trees from the point of view.

PLANT GROWTH MODELING USING L-SYSTEM APPROACH AND ITS VISUALIZATION

The visualization of plant growth modeling using computer simulation has rarely been conducted with Lindenmayer System (L-System) approach. L-System generally has been used as framework for improving and designing realistic modeling on plant growth. It is one kind of tools for representing plant growth based on grammar sintax and mathematic formulation. This research aimed to design modeling and visualizing plant growth structure generated using L-System. The environment on modeling design used three dimension graphic on standart OpenGL format. The visualization on system design has been developed by some of L-System grammar, and the output graphic on three dimension reflected on plant growth as a virtual plant growth system. Using some of samples on grammar L-System rules for describing of the charaterictics of plant growth, the visualization of structure on plant growth has been resulted and demonstrated.

AN INTELLIGENT LEARNING APPROACH TO L-GRAMMAR EXTRACTION FROM IMAGE SEQUENCES OF REAL PLANTS

In this paper, we propose an automatic analyzing and transforming approach to L-system grammar extraction from real plants. Instead of using manually designed rules and cumbersome parameters, our method establishes the relationship between L-system grammars and the iterative trend of botanical entities, which reflect the endogenous factors that caused the plant branching process. To realize this goal, we use a digital camera to take multiple images of unfoliaged (leafless) plants and capture the topological and geometrical data of plant entities using image processing methods. The data then stored into specific data structures. A Hidden Markov based statistical model is then employed to reveal the hidden relations of plant entities which have been classified into categories based on their statistical properties extracted by a classic EM algorithm, the hidden relations have been integrated into the target L-system as grammars. Results show that our method is capable of automatically generating L-grammars for a given unfoliaged plant no matter what branching type it is belongs to.

A THEORETICAL FRAMEWORK MAPPING GRAMMAR BASED SYSTEMS AND FRACTAL DESCRIPTION

In this work, we propose a new method to describe fractal shapes using parametric L-systems. This method consists of introducing scaling factors in the production rules of the parametric L-system grammars. We present a turtle monoid on which we base our calculations to show the exact mathematical relation between L-systems and iterated function systems (IFS); we then establish the conditions for the scaling factors to produce plants' and curves' fractal shapes from parametric L-systems. We demonstrate that with specific values of the scaling factors, we find the exact relationship established by Prusinkiewicz and Hammel between L-systems and IFS. Finally, we present some examples of fractal plant forms and curves created using parametric L-systems with scaling factors.