Image Based Rendering: Using High Dynamic Range Photographs to Light Architectural Scenes

Abstract

Three‐dimensional digital models are becoming more and more common in the architectural profession as communication tools. Whether used in place of physical models or to supplement them, the digital model provides additional visual information that can easily be conveyed, such as building materials, interaction with the environment, changes through time, and lighting. Especially in initial design stages, it is common to have digital models composed of basic forms, communicating the geometry of a proposed building, but as the design process gets into more detail, the models incorporate more information. Renderings of these digital models often attempt to produce a realistic depiction of the building, as close to the visual experience of the built environment as possible. Most currently available digital rendering engines create lighting effects based on a fabricated light source (created according to rules for that renderer) and a prescribed number of light‐bounces off of materials. This is not always accurate, can be computationally expensive, and may also be misleading when used as the basis for design decisions. Digital modeling programs tend to provide a multitude of lighting options, many of which affect the lighting in unrealistic ways. The complexity and availability of unrealistic options can easily confuse the user and result in a poorly lit digital environment that does not accurately predict the final appearance of a design.