Selective rendering for efficient ray traced stereoscopic images

Depth-related visual effects are a key feature of many virtual environments. In stereo-based systems, the depth effect can be produced by delivering frames of disparate image pairs, while in monocular environments, the viewer has to extract this depth information from a single image by examining details such as perspective and shadows. This paper investigates via a number of psychophysical experiments, whether we can reduce computational effort and still achieve perceptually high-quality rendering for stereo imagery. We examined selectively rendering the image pairs by exploiting the fusing capability and depth perception underlying human stereo vision. In ray-tracing-based global illumination systems, a higher image resolution introduces more computation to the rendering process since many more rays need to be traced. We first investigated whether we could utilise the human binocular fusing ability and significantly reduce the resolution of one of the image pairs and yet retain a high perceptual quality under stereo viewing condition. Secondly, we evaluated subjects' performance on a specific visual task that required accurate depth perception. We found that subjects required far fewer rendered depth cues in the stereo viewing environment to perform the task well. Avoiding rendering these detailed cues saved significant computational time. In fact it was possible to achieve a better task performance in the stereo viewing condition at a combined rendering time for the image pairs less than that required for the single monocular image. The outcome of this study suggests that we can produce more efficient stereo images for depth-related visual tasks by selective rendering and exploiting inherent features of human stereo vision

Power Generation and Visual Comfort Performance of Photovoltaic Toplighting Technologies in Transient Spaces

Advances in long-span glazed structures and interest in high-performance building design has proliferated semi-conditioned spaces with large areas of overhead glazing. These spaces are often programmed with intermittent occupation where variability of the indoor climate is an intentional factor of the experience. Technological options for glazed canopy structures have likewise evolved, gaining functions such as power generation which diversifies the benefits of overhead glazing beyond weather protection and daylighting. Here we model the multiple benefits of current and emerging toplighting technologies deployed in the overhead glazing of a train station and compare power generation and visual comfort. A common building integrated photovoltaic system comprised of monocrystalline cells embedded in the interlayer of laminated glazing is compared with a dynamic, tracking solar collector technology that concentrates and largely intercepts direct solar energy but is transmissive to diffuse sky radiation. The concentrating system generates 6% more power annually with a 70% higher peak power production compared to a typical fixed PV system while at times significantly reducing glare

Класифікація дистрибутивних функцій відбивної здатності поверхні

The Bidirectional Reflectance Distributive Function classification according to the various properties is proposed

A parametric sensitivity analysis of the impact of built environment geometrical variables on building energy consumption

The growth of urban communities creates the need for analytical frameworks that have a multiobjective and holistic approach. It is important to integrate these frameworks within commonly used architectural tools. The urban environment is mostly designed and formed by architects and urban planners who can create more sustainable urban growth. In this paper, urban geometry will be explored as it has a significant influence on the building heat loss/gain that determines the energy demand needed to achieve indoor thermal comfort. Simulation tools have been created to analyse and optimize urban geometrical variables in a multiobjective approach. This study analysed urban geometrical variables such as (height, capacity, orientation and window to wall ratio). In addition, it gives an insight of the buildings’ inter-shadowing effect by adding the context buildings’ capacity in the grid. The results show that daylighting analysis consumes almost triple the time using multi-objective, multi-zone geometrical iterations. In this set of inputs for hot arid climates there is a minor impact on cooling energy consumption, suggesting that the study daylighting distribution should be postponed to a later design stage rather being a key component of energy analysis in early design stage. This study shows that WWR has the highest impact on the building thermal cooling consumption in this urban context, then comes built area ratio and finally building height for midrise residential buildings

Evaluating Advanced Facade Systems for Commercial Buildings

Proponents of energy efficiency and sustainability in the built environment have always understood the importance of the facade as a key element for a building to achieve these aims. In recent times the multiple roles played by the facade in providing natural light, enhancing visual amenity and improving thermal comfort has come to the fore. This is in no small measure due to improvements in technology being achieved at low costs. A number of international and local buildings have demonstrated the effectiveness of a facade to resolve aesthetic priorities against performance requirements. These buildings stand apart from others in part because of the level of detail in the resolution of the facade, and its integration with the other building systems

A case study evaluation: perceptually accurate textured surface models

This paper evaluates a new method for capturing surfaces with variations in albedo, height, and local orientation using a standard digital camera with three flash units. Similar to other approaches, captured areas are assumed to be globally flat and largely diffuse. Fortunately, this encompasses a wide array of interesting surfaces, including most materials found in the built environment, e.g., masonry, fabrics, floor coverings, and textured paints. We present a case study of naïve subjects who found that surfaces captured with our method, when rendered under novel lighting and view conditions, were statistically indistinguishable from photographs. This is a significant improvement over previous methods, to which our results are also compared. © 2009 ACM

View-Based Luminance Mapping in Open Workplace

This paper introduces a novel computational method for mapping indoor luminance values on the facade of an open workplace to improve its daylight performance. 180-degree fisheye renderings from different indoor locations, view positions, and times of the year are created. These renderings are then transformed from two-dimensional (2D) images into three-dimensional (3D) hemispheres. High luminance values are filtered and projected from the hemisphere to the facade surface. This framework will highlight the areas of the facade that allow too much light penetration into the interior environment. The flexible workflow allows occupant centric lighting analysis that computes multiple design parameters and synthesizes results for localized facade optimization and daylight design