The visual harmony between new and old materials in the restoration of historical architecture: a study of computer simulation

In the research of historical architecture restoration, scholars respectively focus on the field of architectural context and architectural archeology (Shi, 1988, 1990, 1991, 1992, 1995; Fu, 1995, 1997; Chiu, 2000) or on architecture construction and the procedure of restoration (Shi, 1988, 1989; Chiu, 1990). How to choose materials and cope with their durability becomes an important issue in the restoration of historical architecture (Dasser, 1990; Wang, 1998).In the related research of the usage and durability of materials, some scholars deem that, instead of continuing the traditional ways that last for hundreds of years (that is to replace new materials with old ones), it might be better to keep the original materials (Dasser, 1990). However, unavoidably, some of the originals are much worn. Thus we have to first establish the standard of eliminating components, and secondly to replace identical or similar materials with the old components (Lee, 1990). After accomplishing the restoration, we often unexpectedly find out that the renewed historical building is too new that the sense of history is eliminated (Dasser, 1990; Fu, 1997). Actually this is the important factor that determines the accomplishment of restoration. In the past, some scholars find out that the contrast and conflict between new and old materials are contributed to the different time of manufacture and different coating, such as antiseptic, pattern, etc., which result in the discrepancy of the sense of visual perception (Lee, 1990; Fu, 1997; Dasser, 1990).In recent years, a number of researches and practice of computer technology have been done in the field of architectural design. We are able to proceed design communication more exactly by the application of some systematic softwares, such as image processing, computer graphic, computer modeling/rendering, animation, multimedia, virtual reality and so on (Lawson, 1995; Liu, 1996). The application of computer technology to the research of the preservation of historical architecture is comparatively late. Continually some researchers explore the procedure of restoration by computer simulation technology (Potier, 2000), or establish digital database of the investigation of historical architecture (Sasada, 2000; Wang, 1998). How to choose materials by the technology of computer simulation influences the sense of visual perception. Liu (2000) has a more complete result on visual impact analysis and assessment (VIAA) about the research of urban design projection. The main subjects of this research paper focuses on whether the technology of computer simulation can extenuate the conflict between new and old materials that imposed on visual perception.The objective of this paper is to propose a standard method of visual harmony effects for materials in historical architecture (taking the Gigi Train Station destroyed by the earthquake in last September as the operating example).There are five steps in this research: 1.Categorize the materials of historical architecture and establish the information in digital database. 2.Get new materials of historical architecture and establish the information in digital database. 3.According to the mixing amount of new and old materials, determinate their proportion of the building; mixing new and old materials in a certain way. 4.Assign the mixed materials to the computer model and proceed the simulation of lighting. 5.Make experts and the citizens to evaluate the accomplished computer model in order to propose the expected standard method.According to the experiment mentioned above, we first address a procedure of material simulation of the historical architecture restoration and then offer some suggestions of how to mix new and old materials.By this procedure of simulation, we offer a better view to control the restoration of historical architecture. And, the discrepancy and discordance by new and old materials can be released. Moreover, we thus avoid to reconstructing “too new” historical architecture