A toolbox for volumetric visualization of light properties

Abstract

In this paper, we introduce a toolbox for the perceptually based visualization of light in a volume, focusing on the visual effects of illumination. First, our visualizations extend the conventional methods from a two-dimensional representation on surfaces to the whole volume of a scene. Second, we extend the conventional methods from showing only light intensity to visualizing three light properties (mean illuminance, primary direction and diffuseness). To make our methods generally available and easily accessible, we provide a web-based tool, to which everybody can upload data, measured by a cubic or simple illuminance meter or even a smartphone-app, and generate a variety of three-dimensional visualizations of the light field. The importance of considering the light field in its full complexity (and thus as a three-dimensional vector field instead of its two-dimensional sections) is widely acknowledged. Our toolbox allows easy access to sophisticated methods for analysing the spatial distribution of light and its primary qualities as well as how they vary throughout space. It is our hope that our results raise interest in ‘third stage’ approaches to lighting research and design, and the toolbox offers a practical solution to this complex problem.

Photon flow: A three-dimensional expression of the light field using volume photon mapping

“…In addition, when there are multiple light sources in the space, it is generally difficult to interpret the light propagation from each illumination vector, because the vector coalesces the individual light directions. The light tubes expression, which can visually delineate the light vector directly, was first suggested by Gershun, 2 and Kartashova et al [12][13][14] elucidated its advantages for expressing the physical and visual light field. This aggregated information nevertheless differs fundamentally from the proposed method, in which the raw photon distribution (flow) is the primary information from which metrics may be derived.…”

“…The light tubes expression, which can visually delineate the light vector directly, was first suggested by Gershun, 2 and Kartashova et al . 12–14 elucidated its advantages for expressing the physical and visual light field. This aggregated information nevertheless differs fundamentally from the proposed method, in which the raw photon distribution (flow) is the primary information from which metrics may be derived.…”

Making the switch from task illumination to ambient illumination standards: Principles and practicalities, including energy implications

“…Xia et al 12,13 have based their research on 'Rather than thinking about the illumination as a medium that makes things visible, modern designers prefer to see lighting principally in terms of how it influences the appearance of peoples' surroundings and creates certain atmospheres'. 12 Meanwhile, Kartasova et al 14 have developed a 'toolkit' of techniques to enable visualisation of three-dimensional illumination properties within the volume of an enclosed space.…”