Architectural Scene Real-time Roaming And Sunlight Simulation

Virtual reality (VR) applications, computer-aided design (CAD) applications and scientific visualizations often need user-steered interactive displays of veiy complex polygonal environments, for which, however, the computation and storage requirements r exceeds the capacity of modem graphics hardware on PC. Thus Image-based rendering (IBR) representations are presented by researchers recently. In the first part, this thesis focuses on the real-time rendering of scenes based on geometric and image simplificaliom In addition, teal-time display of virtual scenes is the key issue for a successful virtual reality system. The simulation of indoor scenes and the indoor duration of sunlight in one day have an essential meaning to real estate clients who want to choose an appropriate room to live in. So in the second part of our article, we introduce computation of imdiazing Iixzrs and sunlight simulation of indoor scenes. In Chapter 1, we first describe the basic concepts and primary characteristics of VR systems. Then we briefly discuss the application of VR in architectural simulation, real-time wa]ktbrough of architectural scenes, and sunlight simulation. In Chapter 2, we introduce some related research works, research contents about real-time walkllmugh of architectural scenes. In Chapter 3, we present a relatively new simplification approach which dynamically represent geometric complexity using textures. This approach discuss how to create a system that renders the nearby subset of a model as geometry and the distant, but visible subset of a model with a texture-based representation. The principal contribution of this algorithm performs smooth transition between geometry and texture by morpbing the near geometry. One novel idea is that it takes advantage of the LaD of geometry and texture. In Chapter 4, the author presents the concrete implementation of the algorithm, which includes the data structures and the description of some procedures. We give present some test results comparing our algorithm with others. In Chapter 5, the author simulates sunlight effects of indoor scenes with astronomical calculation and computer graphics rendering. The rendered phenomena look like real sunlight streaming into an interior through an outside window At first, users interactively input date, location of the observed room, and turbidity of atmosphere. With these parameters, we can then calculate the sun's angle of altitude, azimuth, and luminous intensity in terms of formula derived from astronomy and geography. By wmparing the sun's angle of altitude to nearby building's angle of altitude at the same sun's azimuth, we can find out whether the observed room can receive the sunlight's irradiation. Accumulating the period of time in which the sun's angle of altitude is larger than that of nearby building's, we obtain the sunlight irradiating hours of observed room. Given the luminous intensity in a room at a specific time, we can also determine the room's energy and the spots receiving sun's direct irradiation. We take sunlight shining from window as parallel lines and find out meshes that have intersections with those lines, and then distribute the sun's energy to those meshes. Thus we can simulate the indoor scenes with radiosity algorithim Finally, we draw the general conclusion of our paper in the last paragraph. Future work plan on this specific topic is also included.