An efficient multi-resolution framework for high quality interactive rendering of massive point clouds using multi-way kd-trees

We present an efficient technique for out-of-core multi-resolution construction and high quality interactive visualization of massive point clouds. Our approach introduces a novel hierarchical level of detail (LOD) organization based on multi-way kd-trees, which simplifies memory management and allows control over the LOD-tree height. The LOD tree, constructed bottom up using a fast high-quality point simplification method, is fully balanced and contains all uniformly sized nodes. To this end, we introduce and analyze three efficient point simplification approaches that yield a desired number of high-quality output points. For constant rendering performance, we propose an efficient rendering-on-a-budget method with asynchronous data loading, which delivers fully continuous high quality rendering through LOD geo-morphing and deferred blending. Our algorithm is incorporated in a full end-to-end rendering system, which supports both local rendering and cluster-parallel distributed rendering. The method is evaluated on complex models made of hundreds of millions of point sample

The Distribution of Ambisonic and Point Source Rendering to Ethernet AVB Speakers

Point source rendering is used by many object-based audio systems to mix audio objects to loudspeaker arrangements. Algorithms such as Distance-Based Amplitude Panning and Vector-Base Amplitude Panning allow for audio objects to have their locations rendered with high precision. It has been shown that in the context of loudspeaker rendering, point sources rendered with Ambisonics are often spatially blurred. However, Ambisonics does have the advantage of being able to create interesting spatial audio effects and ambient scenes can be recorded using Ambisonic microphones. This paper intends to highlight the advantages that may be gained by combining Ambisonics with virtual point source rendering. It is well known that the processing required for rendering both point source and Ambisonics can have a large overhead. To mitigate this, a distributed spatial audio system based on Ethernet AVB and distributed endpoint processors is modified to incorporate both point source rendering and Ambisonics. An example is given of how point source rendering can be integrated with Ambisonics using this system with existing software

A framework for realistic real-time walkthroughs in a VR distributed environment

Virtual and augmented reality (VR/AR) are increasingly being used in various business scenarios and are important driving forces in technology development. However the usage of these technologies in the home environment is restricted due to several factors including lack of low-cost (from the client point of view) highperformance solutions. In this paper we present a general client/server rendering architecture based on Real-Time concepts, including support for a wide range of client platforms and applications. The idea of focusing on the real-time behaviour of all components involved in distributed IP-based VR scenarios is new and has not been addressed before, except for simple sub-solutions. This is considered as “the most significant problem with the IP environment” [1]. Thus, the most important contribution of this research will be the holistic approach, in which networking, end-systems and rendering aspects are integrated into a cost-effective infrastructure for building distributed real-time VR applications on IP-based networks

A system-theoretic framework for privacy preservation in continuous-time multiagent dynamics

In multiagent dynamical systems, privacy protection corresponds to avoid disclosing the initial states of the agents while accomplishing a distributed task. The system-theoretic framework described in this paper for this scope, denoted dynamical privacy, relies on introducing output maps which act as masks, rendering the internal states of an agent indiscernible by the other agents as well as by external agents monitoring all communications. Our output masks are local (i.e., decided independently by each agent), time-varying functions asymptotically converging to the true states. The resulting masked system is also time-varying, and has the original unmasked system as its limit system. When the unmasked system has a globally exponentially stable equilibrium point, it is shown in the paper that the masked system has the same point as a global attractor. It is also shown that existence of equilibrium points in the masked system is not compatible with dynamical privacy. Application of dynamical privacy to popular examples of multiagent dynamics, such as models of social opinions, average consensus and synchronization, is investigated in detail.Comment: 38 pages, 4 figures, extended version of arXiv preprint arXiv:1808.0808

Parallel rendering

Journal ArticleMassively parallel computers have emerged as valuable tools for performing scientific and engineering computations, far outstripping the capabilities of independent workstations in both sheer floating point performance and memory capacity. As the resolution of simulation models increases, graphics algorithms that take advantage of the large memory and parallelism of these architectures are becoming increasingly important. This issue of IEEE Parallel & Distributed Technology highlights some recent work in parallel computer graphics, specifically parallel rendering

Remote Execution for 3D Graphics

Mobile clients such as PDAs, laptops, wrist watches, smart phones are rapidly emerging in the consumer market and an increasing number of graphics applications are being developed for them. However, current hardware technology limits the processing power on these mobile devices and wireless network bandwidth can be scarce and unreliable. A modern photorealistic graphics application is resource-hungry, consumes large amounts of cpu cycles, memory and network bandwidth if distributed. Besides running them on mobile devices may also diminish their battery power in the process. Bulk of graphics computations involve floating point operations and the lack of hardware support for such on PDAs imposes further restrictions. Remote execution, wherein part or the entire rendering process is offloaded to a powerful surrogate server is an attractive solution. We propose pipeline-splitting, a paradigm whereby 15 sub-stages of the graphics pipeline are isolated and instrumented with networking code such that it can run on either a graphics client or a surrogate server. To validate our concepts, we instrument Mesa3D, a popular implementation of the OpenGL graphics to support pipeline-splitting, creating Remote Mesa (RMesa). We further extend the Remote Execution model to provide an analytical model for predicting the rendering time and memory consumption involved in Remote Execution. Mobile devices have limited battery power. Therefore, it is important to understand if during Remote Execution, communication is more power consuming than computation. In order to study the same, we develop PowerSpy, a Real Time Power Profiler for I/O devices and applications. Finally, we add Remote Execution to an existing Distributed Graphics Framework targeted for mobile devices, namely, MADGRAF. In addition to Remote Execution, MADGRAF has another policy known as the Transcoder Based Approach in which the original 3D graphics image is modified to suite the mobile devices\u27 rendering capacity. Though this speeds up the rendering process, it affects photorealism. We propose an intelligent runtime decision making engine, Intelligraph, which evaluates the runtime performance of the mobile client and decides between Remote Execution and the Transcoder Based Approach

Master of Science

thesisVirtual point lights (VPLs) provide an effective solution to global illumination computation by converting the indirect illumination into direct illumination from many virtual light sources. This approach results in a less noisy image compare to Monte Carlo methods. In addition, the number of VPLs to generate can be specified in advance; therefore, it can be adjusted depending on the scene, desired quality, time budget, and the available computational power. In this thesis, we investigate a new technique that carefully places VPLs for providing improved rendering quality for computing global illumination using VPLs. Our method consists of three different passes. In the first pass, we randomly generate a large number of VPLs in the scene starting from the camera to place them in positions that can contribute to the final rendered image. Then, we remove a considerable number of these VPLs using a Poisson disk sample elimination method to get a subset of VPLs that are uniformly distributed over the part of the scene that is indirectly visible to the camera. The second pass is to estimate the radiant intensity of these VPLs by performing light tracing starting from the original light sources in the scene and scatter the radiance of light rays at a hit-point to the VPLs close to that point. The final pass is rendering the scene, which consists of shading all points in the scene visible to the camera using the original light sources and VPLs