Realistic Lighting Scenarios in Mediterranean ArchitectureEffective use of modeling in conjunction with creative lighting techniques to generate realistic stillimagesAbstractA closed room of Mediterranean architecture was modeled to conduct realistic lighting experiments tostudy the requirements to achieve a variety of specific effects. After careful consideration, POV-Ray, amulti-platform freeware raytracer, was selected for its features and flexibility. Realistic lighting requireda realistic model; the room was constructed to exacting dimensions to ensure a proper fit. Thereplication of objects was used to quickly generate the room while maintaining a high degree ofaccuracy and realism in design. Central features to the room are a skylight in the ceiling and a pool ofwater in the middle. Various lighting scenarios were conducted, experimenting with kinds of lights, theirposition, and their interaction with objects, especially glass and water. Further lighting scenarios weredesigned with atmospheric dust and flames. The result was a series of still images that illustrate thedifficulty in designing a realistic lighting scenario. While realistic modeling can be extremely effective,realistic lighting is absolutely crucial to a successful raytraced image.The team consists of Ajay Kulkarni and Charles Yoon, students in MIT 6.837 Computer Graphics.IntroductionMIT 6.837 Computer Graphics deals with many issues related to computer graphics, from rendering astraight line on the screen to realtime 3D graphics. However, while it deals with many different issuesrelated to the design rationale of computer graphics, we found that it did not spend a great deal of timeon the creation of realistic images. Two problem sets were spent on the design of objects and scenes, butthey were more concerned with modeling than anything else. An extremely accurate model of a car canbe made by taking the CAD file for a car, for example, and putting them into a ray tracer. However, tomake it appear realistic, it takes far more than that: it takes realistic textures and lighting. Our projectfocuses on the latter.Because ray tracing focuses on the pathways of light, the correct placement, attenuation, reflection,refraction, and transmission of lights is critical to realism. This information is useful to anyoneinterested in creating realistic scenes or anyone interested in experimenting with lighting. For example,an interior designer may be interested in experimenting upon a different lighting technique for a largeroom. Studies which deal specifically with light would be able to maximizing the realism in the resultingimage, giving the designer the best possible concept of what a particular scenario would look like.While many people assume that ray tracing is largely about realistic models, the lights are the part thatmake it entirely visible and give it life. As a result, it is critical that everyone involved with computergraphics understands what it takes to build a scene with effective lighting.GoalsModelingBecause the construction of complex, realistic lighting scenarios requires a realistic model, this portionis key to the success of the rest of the project. A suitable architectural model was to be designed andconstructed. Key design parameters included a structure which could be lighted in an "interesting"manner, ease of modeling, and an overall satisfying appeal.LightingWe were interested in using different kinds of lighting, so we intended to study every kind of lightingthat our raytracer could provide. A list of lighting scenarios should be compiled and experimented upon.Examples include, lighting with point light sources, spotlights, torches, obscured lighting, and reflectedlighting. Particularly of interest is lighting in conjunction with objects, such as glass, water, andatmosphere. In addition to raytracing, radiosity will be used if time constraints permit, to create morerealism in the scene.AnimationOnce the lighting studies are complete and images have been rendered, an animation was to begenerated highlighting what we had found. The intention was to do either a fly-through or an animatedchange of lighting or a combination of both.AchievementsInitial DesignWhen we sat down to actually design the model, we intended to design a room with gothic architecture.The gothic architecture was selected for its innate geometric beauty while maintaining very interestingopportunities for lighting and shadows. However, this idea was soon replaced with a decision to use aMediterranean architecture instead. The rationale was that Mediterranean architecture was moreconducive to a light study. To make gothic architecture realistic, it often calls for dark rooms and sparselighting. We were more interested in using alternative lighting, including brightly lighting a room --something that would seem out of place for a gothic piece of architecture. In addition, the Mediterraneanstyle was easier to model with a minimum sacrifice to interesting design.By the end of the project, we found that we used a bit of gothic architecture irregardless, particularly inthe influence over the arches and the vaulted ceiling. However, the room still maintains a veryMediterranean look. The look was loosely based mostly on Charles’s memory of architecture seenfirst-hand as well as "what seemed appropriate." Realism of modeling is not intended to suggest that itthe model is based on an actual design.Selecting a RaytracerBefore we could actually start modeling, we decided that it was best to select a raytracer that was notonly capable of doing everything that we wanted, but one which was easy to use. Some researchindicated that POV-Ray was the best choice for us due to a number of reasons.Primarily, it had a rich feature set that was easy to learn yet powerful enough to manifest our designparameters. Its modeling commands were straightforward and easy to use, enabling us to generate awide variety of complex shapes without having to rely upon specialized modeling tools. In addition, thekinds of lighting and effects that were already built into the program were also well-developed. Inparticular, we liked its ability to handle media, which is designed to simulate halos, dust, and otheratmospheric and volumetric effects. Its ability to handle radiosity as well as raytracing was attractive aswell.Secondly, POV-ray was freeware. This is an important design consideration, especially for us, becausewe do not have the resources to purchase
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