GENERATION OF FORESTS ON TERRAIN WITH DYNAMIC LIGHTING AND SHADOWING

The purpose of this research project is to exhibit an efficient method of creating dynamic lighting and shadowing for the generation of forests on terrain. In this research project, I use textures which contain images of trees from a bird’s eye view in order to create a high scale forest. Furthermore, by manipulating the transparency and color of the textures according to the algorithmic calculations of light and shadow on terrain, I provide the functionality of dynamic lighting and shadowing. Finally, by analyzing the OpenGL pipeline, I design my code in order to allow efficient rendering of the forest

Multiresolution Foliage Rendering

Ponència presentada en CoSECiVi 2020, VI Congreso de la Sociedad Española para las Ciencias del Videojuego On-line, 7-8 d'octubre de 2020.This work presents a continuous level of detail representation of foliage of trees. Multiresolution modeling allows to adapt the number of polygons to render to the relevance of the object in the scene. However, foliage is represented by isolated polygons, so most of the multiresolution modeling methods do not work properly with this part of the tree. This paper presents a multiresolution model that allows to adapt the number of leaves to the relevance of the foliage in the scene. The criterion to select the appropriate leaves to render is based on a previously performed view-driven simplification. To adapt this parameter in real time, data structures and the necessary algorithms that allow us to extract the appropriate number of polygons are presented. Some tests have been developed to evaluate the proposed solution and results show the good performance of the presented continuous level of detail

Plausible reconstruction ans rendering of semi-procedural landscapes

We present a new method for the reconstruction of tree crowns from a single photograph, as well as an efficient representation to render them. The obtained model is used in our terrain viewer application to navigate through large forests with several thousands of trees in real time

Interactive Visualization of Virtual Orchard

Colloque avec actes et comité de lecture. internationale.International audienceIn the application in agriculture and forestry of modeling and simulation of three-dimensional plant growth, interactive visualization of virtual plant community using recently developed model processing and model simplification technology in computer graphics and virtual reality becomes a new focus. The new methods in this paper are the simplifications of models with special shapes: Progressive Leaves Union and View-Dependent Branch Mesh Reorganization, where the originalities include: (1) topological structure modifying progressive simplification with error analysis for sparse parts of a plant, i.e., leaves, flowers and fruits; (2) multi-resolution remeshing for continuous parts, mainly branches; (3) simplification degree determined by viewpoint position, permitted errors, display resolution, and different positions of plants. Therefore, plant models with high proportional simplification are obtained keeping original visual effect within permission scope. Plant modeling and the growth simulation methods in AMAP team are used and plant-positioning data are generated from software AMAP-OrchestraTM as data source. An interactive navigation in virtual orchard is accomplished, and a virtual apple orchard is presented as an example. All of this work is taken in the organization and environment of the high performance computation and visualization in ISA and SILVES projects of INRIA

Procedural Generation and Rendering of Realistic, Navigable Forest Environments: An Open-Source Tool

Simulation of forest environments has applications from entertainment and art creation to commercial and scientific modelling. Due to the unique features and lighting in forests, a forest-specific simulator is desirable, however many current forest simulators are proprietary or highly tailored to a particular application. Here we review several areas of procedural generation and rendering specific to forest generation, and utilise this to create a generalised, open-source tool for generating and rendering interactive, realistic forest scenes. The system uses specialised L-systems to generate trees which are distributed using an ecosystem simulation algorithm. The resulting scene is rendered using a deferred rendering pipeline, a Blinn-Phong lighting model with real-time leaf transparency and post-processing lighting effects. The result is a system that achieves a balance between high natural realism and visual appeal, suitable for tasks including training computer vision algorithms for autonomous robots and visual media generation.Comment: 14 pages, 11 figures. Submitted to Computer Graphics Forum (CGF). The application and supporting configuration files can be found at https://github.com/callumnewlands/ForestGenerato

Fast Rendering of Forest Ecosystems with Dynamic Global Illumination

Real-time rendering of large-scale, forest ecosystems remains a challenging problem, in that important global illumination effects, such as leaf transparency and inter-object light scattering, are difficult to capture, given tight timing constraints and scenes that typically contain hundreds of millions of primitives. We propose a new lighting model, adapted from a model previously used to light convective clouds and other participating media, together with GPU ray tracing, in order to achieve these global illumination effects while maintaining near real-time performance. The lighting model is based on a lattice-Boltzmann method in which reflectance, transmittance, and absorption parameters are taken from measurements of real plants. The lighting model is solved as a preprocessing step, requires only seconds on a single GPU, and allows dynamic lighting changes at run-time. The ray tracing engine, which runs on one or multiple GPUs, combines multiple acceleration structures to achieve near real-time performance for large, complex scenes. Both the preprocessing step and the ray tracing engine make extensive use of NVIDIA\u27s Compute Unified Device Architecture (CUDA)

Progressive Polygon Foliage Simplification

Colloque avec actes et comité de lecture. nationale.National audienceA leaf polygon decimation method, Progressive Leaves Union (PLU), is presented to gradually diminish the number of sparse polygons while approximately keeping the spatial occupation and color distribution of the foliage. In each step of decimation, a new leaf is constructed to represent other two leaves close in position and similar in united. All steps of simplification are recorded in preprocessing, and appropriate simplified models are chosen for different viewing positions and for different resolutions in vizualisation. Experiments have shown that PLU keeps visual effect of original foliage, and when combined with branch polygon simplification, is efficient for multi-resolution representation and view-dependent plant community visualization

Streaming of Plants in Distributed Virtual Environments

International audienceJust as in the real world, plants are important objects in virtual world for creating pleasant and realistic environments, especially those involving natural scenes. As such, much effort has been made in realistic modeling of plants. As the trend moves towards networked and distributed virtual environment, however, the current models are inadequate as they are not designed for progressive transmissions. In this paper, we fill in this gap by proposing a progressive representation for plants based on generalized cylinders. To facilitate the transmission of the plants, we quantify the visual contribution of each branch and use this weight in packet scheduling. We show the efficiency of our representations and effectiveness of our packet scheduler through simulations