Interactive Vegetation Rendering with Slicing and Blending

Detailed and interactive 3D rendering of vegetation is one of the challenges of traditional polygon-oriented computer graphics, due to large geometric complexity even of simple plants. In this paper we introduce a simplified image-based rendering approach based solely on alpha-blended textured polygons. The simplification is based on the limitations of human perception of complex geometry. Our approach renders dozens of detailed trees in real-time with off-the-shelf hardware, while providing significantly improved image quality over existing real-time techniques. The method is based on using ordinary mesh-based rendering for the solid parts of a tree, its trunk and limbs. The sparse parts of a tree, its twigs and leaves, are instead represented with a set of slices, an image-based representation. A slice is a planar layer, represented with an ordinary alpha or color-keyed texture; a set of parallel slices is a slicing. Rendering from an arbitrary viewpoint in a 360 degree circle around the center of a tree is achieved by blending between the nearest two slicings. In our implementation, only 6 slicings with 5 slices each are sufficient to visualize a tree for a moving or stationary observer with the perceptually similar quality as the original model

A Tool for the Creation and management of level-of-detail models for 3D applications

Real-time visualization of 3D scenes is a very important feature of many computer graphics solutions. Current environments require complex scenes which contain an increasing number of objects composed of thousands or even millions of polygons. Nevertheless, this complexity poses a problem for achieving interactive rendering. Among the possible solutions, stripification, simplification and level of detail techniques are very common approaches to reduce the rendering cost. In this paper, we present set of techniques which have been developed for offering higher performance when rendering 3D models in real-time applications. Furthermore, we also present a standalone application useful to quickly simplify and generate multiresolution models for arbitrary geometry and for tree

Real time ray tracing of skeletal implicit surfaces

Modeling and rendering in real time is usually done via rasterization of polygonal meshes. We present a method to model with skeletal implicit surfaces and an algorithm to ray trace these surfaces in real time in the GPU. Our skeletal representation of the surfaces allows to create smooth models easily that can be seamlessly animated and textured. The ray tracing is performed at interactive frame rate thanks to an acceleration data structure based on a BVH and a kd-tree

Interactive inspection of complex multi-object industrial assemblies

The final publication is available at Springer via http://dx.doi.org/10.1016/j.cad.2016.06.005The use of virtual prototypes and digital models containing thousands of individual objects is commonplace in complex industrial applications like the cooperative design of huge ships. Designers are interested in selecting and editing specific sets of objects during the interactive inspection sessions. This is however not supported by standard visualization systems for huge models. In this paper we discuss in detail the concept of rendering front in multiresolution trees, their properties and the algorithms that construct the hierarchy and efficiently render it, applied to very complex CAD models, so that the model structure and the identities of objects are preserved. We also propose an algorithm for the interactive inspection of huge models which uses a rendering budget and supports selection of individual objects and sets of objects, displacement of the selected objects and real-time collision detection during these displacements. Our solution–based on the analysis of several existing view-dependent visualization schemes–uses a Hybrid Multiresolution Tree that mixes layers of exact geometry, simplified models and impostors, together with a time-critical, view-dependent algorithm and a Constrained Front. The algorithm has been successfully tested in real industrial environments; the models involved are presented and discussed in the paper.Peer ReviewedPostprint (author's final draft

Gerçek zamanlı sahnelerin ışıklandırılmasına yardımcı, dinamik voxelleştirme teknikleri.

In this thesis, we focus on approximating indirect illumination on real-time applications to visualize realistic scenes. In order to approximate indirect illumination we provide a fast sparse voxel tree structure for highly dynamic scenes. Our system tries to cover traditional real-time animation methods including dynamic non-deforming objects and objects that deform with bone transformations. The voxel scene data structure is designed for fully dynamic objects and eliminates the voxelization of the dynamic objects per frame which in turn facilitates efficient realistic rendering. We combine this new scene information structure with the widely used real-time rendering techniques and these techniques’ data structures such as shadow mapping and deferred rendering to provide an efficient cone ray-casting algorithm that achieves global illumination in real-time. M.S. - Master of Scienc

Real-time rendering and physics of complex dynamic terrains modeled as CSG trees of DEMs carved with spheres

We present a novel proposal for modeling complex dynamic terrains that offers real-time rendering, dynamic updates and physical interaction of entities simultaneously. We can capture any feature from landscapes including tunnels, overhangs and caves, and we can conduct a total destruction of the terrain. Our approach is based on a Constructive Solid Geometry tree, where a set of spheres are subtracted from a base Digital Elevation Model. Erosions on terrain are easily and efficiently carried out with a spherical sculpting tool with pixel-perfect accuracy. Real-time rendering performance is achieved by applying a one-direction CPU–GPU communication strategy and using the standard depth and stencil buffer functionalities provided by any graphics processor.This work has been partially funded by Ministeri de Ciència i Innovació (MICIN), Agencia Estatal de Investigación (AEI) and the Fons Europeu de Desenvolupament Regional (FEDER) (project PID2021-122136OB-C21 funded by MCIN/AEI/10.13039/50110001 1033/FEDER, UE).Postprint (published version

Efficient 3D stereo vision stabilization for multi-camera viewpoints

In this paper, an algorithm is developed in 3D Stereo vision to improve image stabilization process for multi-camera viewpoints. Finding accurate unique matching key-points using Harris Laplace corner detection method for different photometric changes and geometric transformation in images. Then improved the connectivity of correct matching pairs by minimizing the global error using spanning tree algorithm. Tree algorithm helps to stabilize randomly positioned camera viewpoints in linear order. The unique matching key-points will be calculated only once with our method. Then calculated planar transformation will be applied for real time video rendering. The proposed algorithm can process more than 200 camera viewpoints within two seconds

Empirical Comparison of Three Existing Methods for Simulating Embers in Computer-generated Fire

This study compares computer-generated embers using three existing methods. While there exists research related to fire propagation, flame rendering, and smoke generation, there is nothing that discusses embers. This study focuses specifically on the generation of an ember's path when it is animated. The three methods selected were the Lattice Boltzmann Model, a 3D fractal tree, and a particle system that uses third-order polynomials. The three methods were compared using three different metrics: memory requirements, time requirements (computational cost), and a subjective visual representation. A different method performed best in each of the three metrics. The particle system had the lowest memory requirements. The 3D fractal tree had the least computational cost. The Lattice Boltzmann Model had the best visual representation. Over all, when rendering embers in a real-time environment, the 3D fractal tree is the best choice. However, if pre-rendering your images, then the Lattice Boltzmann Model is best.Computer Science Departmen

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