Computer Aided Design (CAD) is increasingly used as a tool in industries varying from automotive to interior design. Digital visualization allows users to design their working and living spaces, and to select materials and colors for future products. The rendering software that is currently available often suggests photorealistic quality. However, visual comparisons of these images with the physical objects they represent reveal that the color accuracy of these methods is not good enough for critical applications such as automotive design. Therefore, we recently developed a spectral pipeline for rendering gonio-apparent materials such as effect coatings. In order to accurately render objects as they appear in a physical environment, this new approach requires a physics-based representation of the illumination surrounding the objects. In the present article we investigate how to physically represent one, well-defined lighting environment. Therefore, we investigated the lighting inside a recent, commercially available light booth that is widely used in the paint and graphical industry. We determined the spatial dimensions of the X-Rite SpectraLight QC light booth, and built a digital geometrical model of this light booth in the Open Source software Blender. We then measured the spectral radiance emitted by the various light sources that are integrated in the luminaire of this light booth, as well as the illuminance on a grid of measurement spots on the platform below the luminaire. Using these measurement data, we were able to develop an accurate physical simulation of the light field inside the light booth. We plan to use the physics-based model of the lighting inside the light booth to set up visual tests in which physical objects inside the physical light booth are visually compared to images showing virtual objects inside the virtual light booth. These visual tests will form the basis for developing improved models for displaying the color and texture of gonio-apparent materials.
Khalil Huraibat, Esther Perales, Alejandro Ferrero, Joaquín Campos, Ivo Van der Lans, Eric Kirchner, "Physics-based modeling of a light booth to improve color accuracy of 3D rendering" in Proc. IS&T London Imaging Meeting 2020: Future Colour Imaging, 2020, pp 54 - 59, https://doi.org/10.2352/issn.2694-118X.2020.LIM-10