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In recent years, many research projects on real-time rendering have focused on the introduction of global illumination effects in order to improve the realism of a virtual scene. The main goal of these works is to find a compromise between the achievable quality of the resulting rendering and the intrinsic high computational cost of global illumination. An established approach is based on the use of Virtual Point Lights, i.e., "fictitious" light sources that are placed on surfaces in the scene. These lights simulate the contribution of light rays emitted by the light sources and bouncing on different objects. Techniques using Virtual Point Lights are often called Many-Lights techniques. In this paper, we propose an extension of a real-time Many-Lights rendering technique characterized by the integration of photometric data in the process of Virtual Point Lights distribution. We base the definition of light sources and the creation of Virtual Point Lights on the description provided in the IES standard format, created by the Illuminating Engineering Society (IES). [ABSTRACT FROM AUTHOR]

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In recent years, many research projects on real-time rendering have focused on the introduction of global illumination effects in order to improve the realism of a virtual scene. The main goal of these works is to find a compromise between the achievable quality of the resulting rendering and the intrinsic high computational cost of global illumination. An established approach is based on the use of Virtual Point Lights, i.e., “fictitious” light sources that are placed on surfaces in the scene. These lights simulate the contribution of light rays emitted by the light sources and bouncing on different objects. Techniques using Virtual Point Lights are often called Many-Lights techniques. In this paper, we propose an extension of a real-time Many-Lights rendering technique characterized by the integration of photometric data in the process of Virtual Point Lights distribution. We base the definition of light sources and the creation of Virtual Point Lights on the description provided in the IES standard format, created by the Illuminating Engineering Society (IES).

Rendering explosions with self-illumination is a challenging problem. Explosions contain animated volumetric light sources immersed in animated smoke that cast volumetric shadows, which play an essential role and are expensive to compute. We propose an efficient solution that redefines this problem as rendering with many animated lights by converting the volumetric lighting data into a large number of point lights. Focusing on temporal coherency to avoid flickering in animations, we introduce lighting grid hierarchy for approximating the volumetric illumination at different resolutions. Using this structure we can efficiently approximate the lighting at any point inside or outside of the explosion volume as a mixture of lighting contributions from all levels of the hierarchy. As a result, we are able to capture high-frequency details of local illumination, as well as the potentially strong impact of distant illumination. Most importantly, this hierarchical structure allows us to efficiently precompute volumetric shadows, which substantially accelerates the lighting computation. Finally, we provide a scalable approach for computing the multiple scattering of light within the smoke volume using our lighting grid hierarchy. Temporal coherency is achieved by relying on continuous formulations at all stages of the lighting approximation. We show that our method is efficient and effective approximating the self-illumination of explosions with visually indistinguishable results, as compared to path tracing. We also show that our method can be applied to other problems involving a large number of (animated) point lights. [ABSTRACT FROM AUTHOR]

This paper proposes a modification of the filtered importance sampling method, and improves the quality of virtual spherical Gaussian light (VSGL)-based real-time glossy indirect illumination using this modification. The original filtered importance sampling method produces large overlaps of and gaps between filtering kernels for high-frequency probability density functions (PDFs). This is because the size of the filtering kernel is determined using the PDF at the sampled center of the kernel. To reduce those overlaps and gaps, this paper determines the kernel size using the integral of the PDF within the filtering kernel. Our key insight is that these integrals are approximately constant, if kernel centers are sampled using stratified sampling. Therefore, an appropriate kernel size can be obtained by solving this integral equation. Using the proposed kernel size for filtered importance sampling-based VSGL generation, undesirable artifacts are significantly reduced with a negligibly small overhead. [ABSTRACT FROM AUTHOR]

Simulating a complex luminaire such as a chandelier is expensive and slow, even using state-of-the-art algorithms. A more practical alternative is to use precomputation to accelerate rendering. Prior approaches cached information on an aperture surface that separates the luminaire from the scene, but many luminaires have large or ill-defined apertures leading to excessive data storage and inaccurate results. In this article, we separate luminaire rendering into illumination and appearance components. A precomputation stage simulates the complex light flow inside the luminaire to generate two data structures: a set of anisotropic point lights (APLs) and a radiance volume. The APLs are located near apparent sources and represent the light leaving the luminaire, allowing its near-and far-field illumination to be accurately and efficiently computed at render time. The luminaire's appearance consists of high- and low-frequency components, which are both visually important. High-frequency components are computed dynamically at render time, while the more computationally expensive low-frequency components are approximated using the precomputed radiance volume. Results are shown for several complex luminaires, demonstrating orders of magnitude faster rendering compared to the best global illumination algorithms and higher fidelity with greatly reduced storage requirements compared to previous precomputed approaches. [ABSTRACT FROM AUTHOR]

Progressive rendering is becoming a popular alternative to precomputational approaches to appearance design. However, progressive algorithms create images exhibiting visual artifacts at early stages. A user study investigated these artifacts' effects on user performance in appearance design tasks. Novice and expert subjects performed lighting and material editing tasks with four algorithms: random path tracing, quasirandom path tracing, progressive photon mapping, and virtual-point-light rendering. Both the novices and experts strongly preferred path tracing to progressive photon mapping and virtual-point-light rendering. None of the participants preferred random path tracing to quasirandom path tracing or vice versa; the same situation held between progressive photon mapping and virtual-point-light rendering. The user workflow didn’t differ significantly with the four algorithms. The Web Extras include a video showing how four progressive-rendering algorithms converged (at http://youtu.be/ck-Gevl1e9s), the source code used, and other supplementary materials. [ABSTRACT FROM PUBLISHER]