Unlimited object instancing in real-time

In this paper, we propose a novel approach to efficient rendering of an unlimited number of 3D objects in real-time. We present a rendering pipeline that is based on a new computer graphics programming paradigm implementing a holistic approach to the virtual scene definition. Using Signed Distance Functions (SDF) for a virtual scene representation, we managed to control the content and complexity of the virtual scene with the use of mathematical equations. In order to solve the limited hardware problem, especially the limited capacity of the GPU memory, we propose a scene element repository which extends the idea of the data based amplification. The content of the repository strongly depends on a 3D object visualization method. One of the most important requirements of the developed pipeline is the possibility to render 3D objects created by artists. In order to achieve that, the object visualization method uses Sparse Voxel Octree (SVO) ray casting. The developed rendering pipeline is fully compatible with the available SVO algorithms. We show how to avoid occlusion errors which can occur in the SDF and SVO integration single-pass rendering pipeline. Finally, in order to control the content and complexity of the virtual scenes in an unlimited way, we propose a collection of global operators applicable to the virtual scene distance function. Developed Unlimited Object Instancing rendering pipeline can be easily integrated with traditional visualization methods, e.g. the triangle rasterization. The only hardware requirement for our approach is the support for compute shaders or any GPGPU API

Methods for Automated Creation and Efficient Visualisation of Large-Scale Terrains based on Real Height-Map Data

Real-time rendering of large-scale terrains is a difficult problem and remains an active field of research. The massive scale of these landscapes, where the ratio between the size of the terrain and its resolution is spanning multiple orders of magnitude, requires an efficient level of detail strategy. It is crucial that the geometry, as well as the terrain data, are represented seamlessly at varying distances while maintaining a constant visual quality. This thesis investigates common techniques and previous solutions to problems associated with the rendering of height field terrains and discusses their benefits and drawbacks. Subsequently, two solutions to the stated problems are presented, which build and expand upon the state-of-the-art rendering methods. A seamless and efficient mesh representation is achieved by the novel Uniform Distance-Dependent Level of Detail (UDLOD) triangulation method. This fully GPU-based algorithm subdivides a quadtree covering the terrain into small tiles, which can be culled in parallel, and are morphed seamlessly in the vertex shader, resulting in a densely and temporally consistent triangulated mesh. The proposed Chunked Clipmap combines the strengths of both quadtrees and clipmaps to enable efficient out-of-core paging of terrain data. This data structure allows for constant time view-dependent access, graceful degradation if data is unavailable, and supports trilinear and anisotropic filtering. Together these, otherwise independent, techniques enable the rendering of large-scale real-world terrains, which is demonstrated on a dataset encompassing the entire Free State of Saxony at a resolution of one meter, in real-time

A Hierarchical Triangulation for Multiresolution Terrain Models

Interactive visualisation of triangulated terrain surfaces is still a problem for virtual reality systems. A polygonal model of very large terrain data requires a large number of triangles. The main problems are the representation rendering efficiency and the transmission over networks. The major challenge is to simplify a model while preserving its appearance. A multiresolution model represents different levels of detail of an object. We can choose the preferable level of detail according to the position of the observer to improve rendering and we can make a progressive transmission of the different levels. We propose a multiresolution triangulation scheme that eliminates the restrictions of the restricted quadtree triangulation and obtains better results.Facultad de Informátic

Evaluation of the usefulness of various simulation technology options for TERPS enhancement

Current approved terminal instrument procedures (TERPS) do not permit the full exploitation of the helicopter's unique flying characteristics. Enhanced TERPS need to be developed for a host of non-standard landing sites and navigation aids. Precision navigation systems such as microwave landing systems (MLS) and the Global Positioning System (GPS) open the possibility of curved paths, steep glide slopes, and decelerating helicopter approaches. This study evaluated the feasibility, benefits, and liabilities of using helicopter cockpit simulators in place of flight testing to develop enhanced TERPS criteria for non-standard flight profiles and navigation equipment. Near-term (2 to 5 year) requirements for conducting simulator studies to verify that they produce suitable data comparable to that obtained from previous flight tests are discussed. The long-term (5 to 10 year) research and development requirements to provide necessary modeling for continued simulator-based testing to develop enhanced TERPS criteria are also outlined

Paralympic cultures: disability as paradigm

This is an article about the Paralympic Games of summer 2012 and the experience of watching them. It rehearses the use of disability as political and cultural identity in relation to theatre and performance studies. Disability identity is not an identity based on similitude, but is a complex and nuanced relationship between singularity of embodied social experience and glimmers of common ground. Taking the works of Rod Michalko and Petra Kuppers as a representative foundation of disability studies, the article offers disability as an epistemological standpoint, a way of thinking, and not an object of thought. The argument works through close readings of three examples to introduce the theatre and performance studies reader to the notion of disability as a paradigm for the consideration of ideas of difference, similitude and identity. The process of reading the Paralympics from the perspective of a disabled person, bike riding sports fan and disability performance scholar gestures to the scope and potential of disability performance studies. The article accumulates three examples of one disabled person navigating a complex set of positions, all of which are iterations of disability. Whilst this critical approach might imply solipsism, the article also considers disability as community

Efficient conservative collision detection for populated virtual worlds

Large virtual worlds, with considerable level of detail are starting to emerge everywhere, from large areas of actual cities to archaeological detailed reconstructions of sites. Populating a virtual world adds an extra touch to the visualization of these worlds, but unfortunately it also brings an extra burden to the system. Several tasks are required when adding animated characters to a virtual world, such as collision detection, path planning and other AI algorithms, rendering of dynamic geometry, amongst others. In here a method for efficient and scalable conservative collision detection, that is able to deal with large scenes and thousands of avatars, is presented. This method does not perform exact collision detection, hence it is conservative. The method is suitable as a basis for path planning algorithms and other AI algorithms where an avatar is often regarded as ’something’ that can be bounded by a cylinder, or a box. The algorithm is capable of dealing with arbitrarily complex 3D worlds, and does not require any a priori knowledge of the geometry

Feature-based terrain editing from complex sketches

We present a new method for first person sketch-based editing of terrain models. As in usual artistic pictures, the input sketch depicts complex silhouettes with cusps and T-junctions, which typically correspond to non-planar curves in 3D. After analysing depth constraints in the sketch based on perceptual cues, our method best matches the sketched silhouettes with silhouettes or ridges of the input terrain. A deformation algorithm is then applied to the terrain, enabling it to exactly match the sketch from the given perspective view, while insuring that none of the user-defined silhouettes is hidden by another part of the terrain. We extend this sketch-based terrain editing framework to handle a collection of multi-view sketches. As our results show, this method enables users to easily personalize an existing terrain, while preserving its plausibility and style.This work was conducted during an internship of Flora Ponjou Tasse at Inria Rhône-Alpes in Grenoble. It was partly supported by the ERC advanced grant EXPRESSIVE.This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S009784931400081