Generation and Rendering of Interactive Ground Vegetation for Real-Time Testing and Validation of Computer Vision Algorithms

During the development process of new algorithms for computer vision applications, testing and evaluation in real outdoor environments is time-consuming and often difficult to realize. Thus, the use of artificial testing environments is a flexible and cost-efficient alternative. As a result, the development of new techniques for simulating natural, dynamic environments is essential for real-time virtual reality applications, which are commonly known as Virtual Testbeds. Since the first basic usage of Virtual Testbeds several years ago, the image quality of virtual environments has almost reached a level close to photorealism even in real-time due to new rendering approaches and increasing processing power of current graphics hardware. Because of that, Virtual Testbeds can recently be applied in application areas like computer vision, that strongly rely on realistic scene representations. The realistic rendering of natural outdoor scenes has become increasingly important in many application areas, but computer simulated scenes often differ considerably from real-world environments, especially regarding interactive ground vegetation. In this article, we introduce a novel ground vegetation rendering approach, that is capable of generating large scenes with realistic appearance and excellent performance. Our approach features wind animation, as well as object-to-grass interaction and delivers realistically appearing grass and shrubs at all distances and from all viewing angles. This greatly improves immersion, as well as acceptance, especially in virtual training applications. Nevertheless, the rendered results also fulfill important requirements for the computer vision aspect, like plausible geometry representation of the vegetation, as well as its consistence during the entire simulation. Feature detection and matching algorithms are applied to our approach in localization scenarios of mobile robots in natural outdoor environments. We will show how the quality of computer vision algorithms is influenced by highly detailed, dynamic environments, like observed in unstructured, real-world outdoor scenes with wind and object-to-vegetation interaction

Randomly Generated 3D Environments for Serious Games

Abstract — This paper describes a variety of methods that can be used to create realistic, random 3D environments for serious games requiring real-time performance. These include the generation of terrain, vegetation and building structures. An interactive flight simulator has been created as proof of concept. An initial evaluation with two small samples of users (remote and hallway) revealed some usability issues but also showed that overall the flight simulator is enjoyable and appears realistic and believable. Keywords – serious games; 3D terrain modeling; computer graphics; flight simulator. I

Real-time rendering and simulation of trees and snow

Tree models created by an industry used package are exported and the structure extracted in order to procedurally regenerate the geometric mesh, addressing the limitations of the application's standard output. The structure, once extracted, is used to fully generate a high quality skeleton for the tree, individually representing each section in every branch to give the greatest achievable level of freedom of deformation and animation. Around the generated skeleton, a new geometric mesh is wrapped using a single, continuous surface resulting in the removal of intersection based render artefacts. Surface smoothing and enhanced detail is added to the model dynamically using the GPU enhanced tessellation engine. A real-time snow accumulation system is developed to generate snow cover on a dynamic, animated scene. Occlusion techniques are used to project snow accumulating faces and map exposed areas to applied accumulation maps in the form of dynamic textures. Accumulation maps are xed to applied surfaces, allowing moving objects to maintain accumulated snow cover. Mesh generation is performed dynamically during the rendering pass using surface o�setting and tessellation to enhance required detail

Dynamic Graph: un outil générique pour la modélisation multi-échelle

National audienceModéliser et afficher des scènes animées avec de grandes variations d'échelle est une tache très coûteuse et aujourd'hui impossible à réaliser en temps-réel. Nous montrons que seule la modélisation procédurale multi- échelle est apte à résoudre un tel problème. Une analyse des quelques travaux existants permet d'une part de constater l'efficacité de cette approche, et d'autre part de mettre en évidence l'un de ses plus gros défauts : la quantité de code à écrire pour créer chaque nouveau modèle. C'est là notre principale contribution : nous présentons Dynamic Graph (DG), le premier outil générique pour la modélisation procédurale multi-échelle. Autour d'un noyau basé sur des graphes acycliques dynamiques, de nombreuses fonctionnalités allègent le processus de création sans pour autant nuire à son expressivité

The Effects of Machinima on Communication Skills in Students with Developmental Dyslexia

Many research efforts in the international literature have been conducted to investigate various fundamental issues associated with communication skills cultivation of students with developmental dyslexia. However, little is known when it comes to the impact that 'immersive technologies', such as three-dimensional virtual worlds, without considering any exploration of their impact to assist boys and girls with developmental dyslexia cultivate communication skills. Motivated by this inadequacy in the literature, the purpose of this study is to explore the effectiveness of the machinima approach, created via OpenSimulator and Scratch4SL, for students with developmental dyslexia in vocabulary learning and practicing. This embedded mixed-methods research was conducted over a four-week timetable in-class course, with forty students (n = 40) aged 10-12 years old. All students were equally separated into two groups in line with their gender. Boys and girls were encouraged to unfold the communication skills developed (i.e., spelling, writing, reading) by creating their own stories, after viewing educational videos and machinima scenes, before and after the treatment. The results indicate that machinima positively affected students' learning outcomes and achievements. Machinima can improve immediate knowledge gains in boys compared to girls to purposefully translate their cognitive thinking into storytelling, when problem-solving situations through simulated realism are considered. This study also offers insights for educational implications and design guidelines for machinima creation, providing empirical evidence on its effect on the participants' linguistics understanding and communication skills for language learning in girls and boys with developmental dyslexia

Art probing and worldmaking. Exploring museum imaginaries

How can artistic creative practice be combined with ethnological cultural analysis? A process based on practices of art probing is proposed and related to discussions about museum imaginaries, digital cultures and sensory aspects of ethnography. The point of departure for the discussion is the audiovisual performance Possible Worlds

Art probing and worldmaking: exploring museum imaginaries

How can artistic creative practice be combined with ethnological cultural analysis? A process based on practices of art probing is proposed and related to discussions about museum imaginaries, digital cultures and sensory aspects of ethnography. The point of departure for the discussion is the audiovisual performance Possible Worlds

Fractal tree modeling: generation, rendering and growth animation

Ankara : Department of Computer Engineering and Information Science and the Institute of Engineering and Science of Bilkent Univ., 1994.Thesis (Master's) -- -Bilkent University, 1994.Includes bibliographical references leaves 45-46.Plant modeling for visual purposes is a challenge, especially when user interaction is a concern. In this thesis, we propose a recursive, time-aware, fractal tree model with realistic features including statistical self-similarity, stochastic pruning and heuristic branch intersections. The main focus is on realistic branch structures. The skeletal model constructed by statistically fractal methods is fleshed out using heuristic acceleration techniques. We develop a system with near real-time feedback for fast model manipulation and viewing. The system implementation is developed on an SGI Iris Indigo XS24 workstation.Ünal, ErsinM.S

Real-time Realistic Rendering Of Nature Scenes With Dynamic Lighting

Rendering of natural scenes has interested the scientific community for a long time due to its numerous applications. The targeted goal is to create images that are similar to what a viewer can see in real life with his/her eyes. The main obstacle is complexity: nature scenes from real life contain a huge number of small details that are hard to model, take a lot of time to render and require a huge amount of memory unavailable in current computers. This complexity mainly comes from geometry and lighting. The goal of our research is to overcome this complexity and to achieve real-time rendering of nature scenes while providing visually convincing dynamic global illumination. Our work focuses on grass and trees as they are commonly visible in everyday life. We handle geometry and lighting complexities for grass to render millions of grass blades interactively with dynamic lighting. As for lighting complexity, we address real-time rendering of trees by proposing a lighting model that handles indirect lighting. Our work makes extensive use of the current generation of Graphics Processing Units (GPUs) to meet the real-time requirement and to leave the CPU free to carry out other tasks