Prof. Dr. André Hinkenjann
Refine
H-BRS Bibliography
- yes (89)
Departments, institutes and facilities
Document Type
- Conference Object (67)
- Article (19)
- Research Data (1)
- Preprint (1)
- Report (1)
Year of publication
Language
- English (89) (remove)
Keywords
- Virtual Reality (4)
- Ray Tracing (3)
- foveated rendering (3)
- 3D user interface (2)
- 3D user interfaces (2)
- Augmented Reality (2)
- Computer Graphics (2)
- Distributed rendering (2)
- Garbage collection (2)
- Java virtual machine (2)
Robust Indoor Localization Using Optimal Fusion Filter For Sensors And Map Layout Information
(2014)
The Render Cache [1,2] allows the interactive display of very large scenes, rendered with complex global illumination models, by decoupling camera movement from the costly scene sampling process. In this paper, the distributed execution of the individual components of the Render Cache on a PC cluster is shown to be a viable alternative to the shared memory implementation.As the processing power of an entire node can be dedicated to a single component, more advanced algorithms may be examined. Modular functional units also lead to increased flexibility, useful in research as well as industrial applications.We introduce a new strategy for view-driven scene sampling, as well as support for multiple camera viewpoints generated from the same cache. Stereo display and a CAVE multi-camera setup have been implemented.The use of the highly portable and inter-operable CORBA networking API simplifies the integration of most existing pixel-based renderers. So far, three renderers (C++ and Java) have been adapted to function within our framework.
We present an interactive system that uses ray tracing as a rendering technique. The system consists of a modular Virtual Reality framework and a cluster-based ray tracing rendering extension running on a number of Cell Broadband Engine-based servers. The VR framework allows for loading rendering plugins at runtime. By using this combination it is possible to simulate interactively effects from geometric optics, like correct reflections and refractions.
The latest trends in inverse rendering techniques for reconstruction use neural networks to learn 3D representations as neural fields. NeRF-based techniques fit multi-layer perceptrons (MLPs) to a set of training images to estimate a radiance field which can then be rendered from any virtual camera by means of volume rendering algorithms. Major drawbacks of these representations are the lack of well-defined surfaces and non-interactive rendering times, as wide and deep MLPs must be queried millions of times per single frame. These limitations have recently been singularly overcome, but managing to accomplish this simultaneously opens up new use cases. We present KiloNeuS, a new neural object representation that can be rendered in path-traced scenes at interactive frame rates. KiloNeuS enables the simulation of realistic light interactions between neural and classic primitives in shared scenes, and it demonstrably performs in real-time with plenty of room for future optimizations and extensions.
Ray Tracing, accurate physical simulations with collision detection, particle systems and spatial audio rendering are only a few components that become more and more interesting for Virtual Environments due to the steadily increasing computing power. Many components use geometric queries for their calculations. To speed up those queries spatial data structures are used. These data structures are mostly implemented for every problem individually resulting in many individually maintained parts, unnecessary memory consumption and waste of computing power to maintain all the individual data structures. We propose a design for a centralized spatial data structure that can be used everywhere within the system.
Interactive rendering of complex models has many applications in the Virtual Reality Continuum. The oil&gas industry uses interactive visualizations of huge seismic data sets to evaluate and plan drilling operations. The automotive industry evaluates designs based on very detailed models. Unfortunately, many of these very complex geometric models cannot be displayed with interactive frame rates on graphics workstations. This is due to the limited scalability of their graphics performance. Recently there is a trend to use networked standard PCs to solve this problem. Care must be taken however, because of nonexistent shared memory with clustered PCs. All data and commands have to be sent across the network. It turns out that the removal of the network bottleneck is a challenging problem to solve in this context.In this article we present some approaches for network aware parallel rendering on commodity hardware. These strategies are technological as well as algorithmic solutions.
Clusters of commodity PCs are widely considered as the way to go to improve rendering performance and quality in many real-time rendering applications. We describe the design and implementation of our parallel rendering system for real-time rendering applications. Major design objectives for our system are: usage of commodity hardware for all system components, ease of integration into existing Virtual Environments software, and flexibility in applying different rendering techniques, e.g. using ray tracing to render distinct objects with a particularly high quality.
This presentation gives an overview of current research in the area of high quality rendering and visualization at the Institute of Visual Computing (IVC). Our research facility has some unique software and hardware installations of which we will describe a large, ultra- high resolution (72 megapixel) video wall in this presentation.
Most VE-frameworks try to support many different input and output devices. They do not concentrate so much on the rendering because this is tradi- tionally done by graphics workstation. In this short paper we present a modern VE framework that has a small kernel and is able to use different renderers. This includes sound renderers, physics renderers and software based graphics renderers. While our VE framework, named basho is still under development we have an alpha version running under Linux and MacOS X.
Phase Space Rendering
(2007)
Real-Time Simulation of Camera Errors and Their Effect on Some Basic Robotic Vision Algorithms
(2013)
Foreword to the Special Section on the Symposium on Virtual and Augmented Reality 2019 (SVR 2019)
(2020)
A recent trend in interactive environments are large, ultra high resolution displays (LUHRDs). Compared to other large interactive installations, like the CAVE tm , LUHRDs are usually flat or (slightly) curved and have a significantly higher resolution, offering new research and application opportunities.
This tutorial provides information for researchers and engineers who plan to install and use a large ultra-high resolution display. We will give detailed information on the hardware and software of recently created and established installations and will show the variety of possible approaches. Also, we will talk about rendering software, rendering techniques and interaction for LUHRDs, as well as applications.
A New Approach of Using Two Wireless Tracking Systems in Mobile Augmented Reality Applications
(2003)
Improving data acquisition techniques and rising computational power keep producing more and larger data sets that need to be analyzed. These data sets usually do not fit into a GPU's memory. To interactively visualize such data with direct volume rendering, sophisticated techniques for problem domain decomposition, memory management and rendering have to be used. The volume renderer Volt is used to show how CUDA is efficiently utilised to manage the volume data and a GPU's memory with the aim of low opacity volume renderings of large volumes at interactive frame rates.
Human beings spend much time under the influence of artificial lighting. Often, it is beneficial to adapt lighting to the task, as well as the user’s mental and physical constitution and well-being. This formulates new requirements for lighting - human-centric lighting - and drives a need for new light control methods in interior spaces. In this paper we present a holistic system that provides a novel approach to human-centric lighting by introducing simulation methods into interactive light control, to adapt the lighting based on the user's needs. We look at a simulation and evaluation platform that uses interactive stochastic spectral rendering methods to simulate light sources, allowing for their interactive adjustment and adaption.
Current computer architectures are multi-threaded and make use of multiple CPU cores. Most garbage collections policies for the Java Virtual Machine include a stop-the-world phase, which means that all threads are suspended. A considerable portion of the execution time of Java programs is spent in these stop-the-world garbage collections. To improve this behavior, a thread-local allocation and garbage collection that only affects single threads, has been proposed. Unfortunately, only objects that are not accessible by other threads ("do not escape") are eligible for this kind of allocation. It is therefore necessary to reliably predict the escaping of objects. The work presented in this paper analyzes the escaping of objects based on the line of code (program counter – PC) the object was allocated at. The results show that on average 60-80% of the objects do not escape and can therefore be locally allocated.
Application performance improvements through VM parameter modification after runtime analysis
(2013)
Designs for decorative surfaces, such as flooring, must cover several square meters to avoid visible repeats. While the use of desktop systems is feasible to support the designer, it is challenging for a non-domain expert to get the right impression of the appearances of surfaces due to limited display sizes and a potentially unnatural interaction with digital designs. At the same time, large-format editing of structure and gloss is becoming increasingly important. Advances in the printing industry allow for more faithful reproduction of such surface details. Unfortunately, existing systems for visualizing surface designs cannot adequately account for gloss, especially for non-domain experts. Here, the complex interaction of light sources and the camera position must be controlled using software controls. As a result, only small parts of the data set can be properly inspected at a time. Also, real-world lighting is not considered here. This work presents a system for the processing and realistic visualization of large decorative surface designs. To this end, we present a tabletop solution that is coupled to a live 360° video feed and a spatial tracking system. This allows for reproducing natural view-dependent effects like real-world reflections, live image-based lighting, and the interaction with the design using virtual light sources employing natural interaction techniques that allow for a more accurate inspection even for non-domain experts.
When navigating larger virtual environments and computer games, natural walking is often unfeasible. Here, we investigate how alternatives such as joystick- or leaning-based locomotion interfaces ("human joystick") can be enhanced by adding walking-related cues following a sensory substitution approach. Using a custom-designed foot haptics system and evaluating it in a multi-part study, we show that adding walking related auditory cues (footstep sounds), visual cues (simulating bobbing head-motions from walking), and vibrotactile cues (via vibrotactile transducers and bass-shakers under participants' feet) could all enhance participants' sensation of self-motion (vection) and involement/presence. These benefits occurred similarly for seated joystick and standing leaning locomotion. Footstep sounds and vibrotactile cues also enhanced participants' self-reported ability to judge self-motion velocities and distances traveled. Compared to seated joystick control, standing leaning enhanced self-motion sensations. Combining standing leaning with a minimal walking-in-place procedure showed no benefits and reduced usability, though. Together, results highlight the potential of incorporating walking-related auditory, visual, and vibrotactile cues for improving user experience and self-motion perception in applications such as virtual reality, gaming, and tele-presence.
In Mixed Reality (MR) Environments, the user's view is augmented with virtual, artificial objects. To visualize virtual objects, the position and orientation of the user's view or the camera is needed. Tracking of the user's viewpoint is an essential area in MR applications, especially for interaction and navigation. In present systems, the initialization is often complex. For this reason, we introduce a new method for fast initialization of markerless object tracking. This method is based on Speed Up Robust Features and paradoxically on a traditional marker-based library. Most markerless tracking algorithms can be divided into two parts: an offline and an online stage. The focus of this paper is optimization of the offline stage, which is often time-consuming.
This paper describes FGPA-based image combining for parallel graphics systems. The goal of our current work is to reduce network traffic and latency for increasing performance in parallel visualization systems. Initial data distribution is based on a common ethernet network whereas image combining and returning differs to traditional parallel rendering methods. Calculated sub-images are grabbed directly from the DVI-Ports for fast image compositing by a FPGA-based combiner.
We present our approach to extend a Virtual Reality software framework towards the use for Augmented Reality applications. Although VR and AR applications have very similar requirements in terms of abstract components (like 6DOF input, stereoscopic output, simulation engines), the requirements in terms of hardware and software vary considerably. In this article we would like to share the experience gained from adapting our VR software framework for AR applications. We will address design issues for this task. The result is a VR/AR basic software that allows us to implement interactive applications without fixing their type (VR or AR) beforehand. Switching from VR to AR is a matter of changing the configuration file of the application. We also give an example of the use of the extended framework: Augmenting the magnetic field of bar magnets in physics classes. We describe the setup of the system and the real-time calculation of the magnetic field, using a GPU.
This paper describes the work done at our Lab to improve visual and other quality of Virtual Environments. To be able to achieve better quality we built a new Virtual Environments framework called basho. basho is a renderer independent VE framework. Although renderers are not limited to graphics renderers we first concentrated on improving visual quality. Independence is gained from designing basho to have a small kernel and several plug-ins.
We present basho, a light weight and easily extendable virtual environment (VE) framework. Key benefits of this framework are independence of the scene element representation and the rendering API. The main goal was to make VE applications flexible without the need to change them, not only by being independent from input and output devices. As an example, with basho it is possible to switch from local illumination models to ray tracing by just replacing the renderer. Or to replace the graphical representation of the scene elements without the need to change the application. Furthermore it is possible to mix rendering technologies within a scene. This paper emphasises on the abstraction of the scene element representation.
Todays Virtual Environment frameworks use scene graphs to represent virtual worlds. We believe that this is a proper technical approach, but a VE framework should try to model its application area as accurate as possible. Therefore a scene graph is not the best way to represent a virtual world. In this paper we present an easily extensible model to describe entities in the virtual world. Further on we show how this model drives the design of our VE framework and how it is integrated.
In presence of conflicting or ambiguous visual cues in complex scenes, performing 3D selection and manipulation tasks can be challenging. To improve motor planning and coordination, we explore audio-tactile cues to inform the user about the presence of objects in hand proximity, e.g., to avoid unwanted object penetrations. We do so through a novel glove-based tactile interface, enhanced by audio cues. Through two user studies, we illustrate that proximity guidance cues improve spatial awareness, hand motions, and collision avoidance behaviors, and show how proximity cues in combination with collision and friction cues can significantly improve performance.
We present a novel forearm-and-glove tactile interface that can enhance 3D interaction by guiding hand motor planning and coordination. In particular, we aim to improve hand motion and pose actions related to selection and manipulation tasks. Through our user studies, we illustrate how tactile patterns can guide the user, by triggering hand pose and motion changes, for example to grasp (select) and manipulate (move) an object. We discuss the potential and limitations of the interface, and outline future work.