LightGuider is a novel guidance-based approach to interactive lighting design, which typically consists of interleaved 3D modeling operations and light transport simulations. Rather than having designers use a trial-and-error approach to match their illumination constraints and aesthetic goals, LightGuider supports the process by simulating potential next modeling steps that can deliver the most significant improvements. LightGuider takes predefined quality criteria and the current focus of the designer into account to visualize suggestions for lighting-design improvements via a specialized provenance tree. This provenance tree integrates snapshot visualizations of how well a design meets the given quality criteria weighted by the designer's preferences. This integration facilitates the analysis of quality improvements over the course of a modeling workflow as well as the comparison of alternative design solutions. We evaluate our approach with three lighting designers to illustrate its usefulness.
In the scientific domain, several approaches automate or simplify light-source placement and orientation---either with procedural methods as suggested by Schwarz and Wonka @cite_11 , or by painting'' the parts of a scene for illumination @cite_3 @cite_15 @cite_8 @cite_23 @cite_28 @cite_41 . While these methods deliver solutions to certain aspects, they ignore the iterative, interactive workflow of lighting designers, in which a large variety of considerations (that may not all be quantifiable) play an important role. Other approaches focus on interactivity, and try to decrease the feedback cycles between modeling and simulation. Both @cite_37 and Kr " @cite_21 rely on fast, GPU-based simulations. Despite being efficient, they do not offer guided modeling proposals or methods to explore and compare parallel modeling tracks.
@cite_37 @cite_8 @cite_28 @cite_41 @cite_21 @cite_3 @cite_23 @cite_15 @cite_11
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We propose a new method for the fast computation of light maps using a many-light global-illumination solution. A complete scene can be light mapped on the order of seconds to minutes, allowing fast and consistent previews for editing or even generation at loading time. In our method, virtual point lights are clustered into a set of virtual polygon lights, which represent a compact description of the illumination in the scene. The actual light-map generation is performed directly on the GPU. Our approach degrades gracefully, avoiding objectionable artifacts even for very short computation times. An interactive and intuitive way of designing lighting around a model is desirable in many applications. In this paper, we present a tool for interactive inverse lighting in which a model is rendered based on sketched lighting effects. To specify target lighting, the user freely sketches bright and dark regions on the model as if coloring it with crayons. Using these hints and the geometry of the model, the system efficiently derives light positions, directions, intensities and spot angles, assuming a local point-light based illumination model. As the system also minimizes changes from the previous specifications, lighting can be designed incrementally. We formulate the inverse lighting problem as that of an optimization and solve it using a judicious mix of greedy and minimization methods. We also map expensive calculations of the optimization to graphics hardware to make the process fast and interactive. Our tool can be used to augment larger systems that use point-light based illumination models but lack intuitive interfaces for lighting design, and also in conjunction with applications like ray tracing where interactive lighting design is difficult to achieve. Lighting design plays a crucial role in indoor lighting design, computer cinematograph and many other applications. Computer-assisted lighting design aims to find a lighting configuration that best approximates the illumination effect specified by designers. In this paper, we present an automatic approach for lighting design, in which discrete and continuous optimization of the lighting configuration, including the number, intensity, and position of lights, are achieved. Our lighting design algorithm consists of two major steps. The first step estimates an initial lighting configuration by light sampling and clustering. The initial light clusters are then recursively merged to form a light hierarchy. The second step optimizes the lighting configuration by alternatively selecting a light cut on the light hierarchy to determine the number of representative lights and optimizing the lighting parameters using the simplex method. To speed up the optimization computation, only illumination at scene vertices that are important to rendering are sampled and taken into account in the optimization. Using the proposed approach, we develop a lighting design system that can compute appropriate lighting configurations to generate the illumination effects iteratively painted and modified by a designer interactively. Light painting is an artform where a light source is moved during a long-exposure shot, creating trails resembling a stroke on a canvas. It is very difficult to perform because the light source needs to be moved at the intended speed and along a precise trajectory. Additionally, images can be corrupted by the person moving the light. We propose computational light painting, which avoids such artifacts and is easy to use. Taking a video of the moving light as input, a virtual exposure allows us to draw the intended light positions in a post-process. We support animation, as well as 3D light sculpting, with high-quality results. We present a new approach to lighting design for image synthesis. It is based on the inverse problem of determining light settings for an environment from a description of the desired solution. The method is useful for determining light intensities to achieve a desired effect in a computer simulation and can be used in conjunction with any rendering algorithm. Given a set of lights with fixed positions, we determine the light intensities and colors that most closely match the target image painted by the designer using a constrained least squares approach. We describe an interactive system that allows flexible input and display of the solution. Lighting is a fundamental aspect of computer cinematography that involves the placement and configuration of lights to establish mood and enhance storytelling. This process is labor intensive as artists repeatedly adjust the parameters of a large set of complex lights to achieve a desired effect. Typical lighting controls affect the final image indirectly, requiring a large number of trials to obtain a suitable result. We present an interactive system wherein an artist paints desired lighting effects directly into the scene, and the computer solves for parameters that achieve the desired look. The artist can paint color, light shape, shadows, highlights, and reflections using a suite of tools designed for painting light. Our system matches these effects using a nonlinear optimizer made robust by a combination of initial estimates, system design, and user-guided optimization. In contrast, previous work on painting light has not permitted the lights to move, allowing for linear optimization but preventing its use in computer cinematography. To demonstrate our approach we lit several scenes, mainly using a direct illumination renderer designed for computer animation, but also including two other rendering styles. We show that painting interfaces can quickly produce high quality lighting setups, easing the lighting artist's workflow. We present a novel scheme for automatically generating line drawings from 2D images, aiming to facilitate effective visual communication. In contrast to conventional edge detectors, our technique imitates the human line drawing process and consists of two parts: line extraction and line rendering. We propose a novel line extraction method based on likelihood-function estimation, which effectively finds the genuine shape boundaries. We consider the feature scale and the blurriness of lines with which the detail and the focus-level of lines are controlled in the rendering. We also employ stroke textures to provide a variety of illustration styles. Experimental results demonstrate that our technique generates various kinds of line drawings from 2D images enabled by the control over detail, focus, and style. We present a system for the lighting design of procedurally modeled buildings. The design is procedurally specified as part of the ordinary modeling workflow by defining goals for the illumination that should be attained and locations where luminaires may be installed to realize these goals. Additionally, constraints can be modeled that make the arrangement of the installed luminaires respect certain aesthetic and structural considerations. From this specification, the system automatically generates a lighting solution for any concrete model instance. The underlying, intricate joint optimization and constraint satisfaction problem is approached with a stochastic scheme that operates directly in the complex subspace where all constraints are observed. To navigate this subspace efficaciously, the actual lighting situation is taken into account. We demonstrate our system on multiple examples spanning a variety of architectural structures and lighting designs.