中国古建筑风格初探(英文)

3D RECONSTRUCTION AND SIMULATING ASSEMBLY OF ANCIENT CHINESE

TIMBER-STRUCTURE BUILDING

D. Lia, T. Honga,Y. Zhub, J. Yanga aState Key Lab of Information Engineering in Surveying Mapping and Remote Sensing, Wuhan University, 129 LuoYu Road, bSchool of Remote Sensing Information Engineering, Wuhan University, 129 LuoYu Road, Wuhan, Hubei, China, 430079,

KEY WORDS: 3D Reconstruction??Points Cloud?? Simulating Assembly??Animation??Collision Detection

ABSTRACT

In this paper, Chi Lin Nunnery, the imitation of early Tang-Dynasty timber-structure building in Hong Kong, is used as an example to perform 3D model reconstruction and demonstrate the assembling process, as well as make a digital database of buildings. This paper gives an introduction to the features of ancient Chinese timber-structure buildings and also the workflow of 3D reconstruction of ancient timber-structure buildings, and mainly discusses about ways of 3D database collection, 3D modeling, collision detection and other key technologies. The research of this article could provide effective methods to protect, research, repair and restore ancient timber-structure buildings and a potent way to manage project’s quality.

can easily catch fire. According to literature recording, from 1. INTRODUCTION

the Forbidden City’s completion to late period of Qing dynasty,

during the 400 years, the number of major fire has amounted to 1.1 Features of Ancient Chinese Buildings

as much as 24 in the major buildings in the court. Besides,

Compared with ancient western buildings, which mainly using humidity, insect, especially war and destructive development masonry structure, one prominent feature of ancient Chinese construction, all will do great harm to ancient timber-structure buildings is the wide employment of timber-structure, every buildings. Although all countries in the world have speared no part of building is joined together by mortise-tenon. effort to strengthen the protection of the historical and cultural

The most remarkable heritage including cultural relics and historic sites??it is a pity

feature of ancient Chinese that a large amount of timber-structure building disappeared in

building is the big roof, the history as the perishing of time. At present, only 3 timber-

which has a large shape structure buildings of Tang dynasty exist in the world, and more

and its curved surface. timber-structure buildings in Tang and Song dynasty can only

The eaves follow suit. be seen in fresco and literature!

Bracing santalums and

rafters under the eaves, 1.2 Study Significance

there is a need for a type

of component on the In the past, timber-structure buildings have such characteristics

column and beam, which like manual operation and oral inheritance, causing it difficult to

is a bow-shaped short timber, named Gong, projecting from the preserve building technologies, as a result, timber-structure

building’s architectural art is lapsing, which adds the difficulty column and beam, adding one layer after another if not enough,

layer after layer, therefore the eaves is far away from the body to reconstruct and protect the ancient buildings.

of house. Between two layers of Traditional recording tools for historic buildings provide

Gongs, there is a kind of square various formats to address different documentation focus, such

timber for padding which is called as Measured drawing, Perspective Drawings, Photography,

Dou. Multi-layer Dous and Gongs Sketching, Videos, Writing and so on??but all have its own

together form “a cluster of limitation. Fortunately, Computers provide us easier and faster

DouGong”. DouGongs and beams storing, retrieving, and sorting information capabilities than

combine into a DouGong layer, traditional tools. By constructing a 3D model of a building, we

like a big elastic pad, which has are actually making a digital database of the building. By

load-transferring and anti-seismic assembly demonstration, we can study the building technology

function. Its shape and size have of ancient buildings, and let ordinary pubic without architecture

become mature in Tang and Song background understand and appreciate building by dynamic

dynasty. However, with the visible browser, so its significance is far-reaching!

development of building materials The study mainly aims at realizing 3D reconstruction of ancient

and technology, body of house timber-structure building, simulating assembly by computer and

mainly use brick and mason, and laber is no longer needed to making information system of ancient building.

reach that far, so DouGong has been reduced in its function as

bracing under the eaves, and its size is shrinking day by day. In 1.3 Case and Workflow Ming and Qing dynasty’s buildings, DouGong no longer has

important structural function but as a decoration. Timber-Timber-structure building structure building presenting and displaying numerous in Tang dynasty is most craftsmen’s intelligence and wisdom has created a marvelous representative. Taking architectural miracle, therefore making China’s ancient building Chin Lin Nunnery for showing a particular looking in the world architecture’s example (figure 3), which picture. is imitation of Tang

The biggest disadvantage of timber-structure building is they dynasty timber-structure

building group in Hong Kong, its components are of various types, its style is vi rile and simple, and the general setting is rigorous and orderly, fully interpreting the artistic charm and building technology of ancient Chinese building.

Chinese ancient timber-structure building is a complicated construction joined by motise-tenon, and in ideal situation (data of building design), all components should be closely knitted without the likelihood of loose structure and impossible assembly. But in effect, a certain degree of deviation is unavoidable, such as precision of timber components mechanical processing, timer’s deformation and so forth. If the error accumulates (sometimes even the problem in design) and can’t be dealt with properly, assembly will face great carefully.

2.1.2 Based on blue print: 2D data can be transformed into 3D data according to the design drawings, and this method is always used to determine object’s shape primarily.

2.1.3 Laser scanning: For the irregular geometrical structure, like lotus on the roof, digital photogrammetry or laser scanning technology can be used.

Development of Laser rangefinding technology represented by laser scanning technology provides human beings with brand-new technological means in spatial information obtaining. Laser scanner can automatically finish its work in attaining points difficulties.

Sticking points can be found through constructing 3D modeling and simulating assembly by computer on the basis of actual sample data, which can not only save timber but also avoid repetitive dismantling. That’s to examine reasonability of components design and analyses manufacture error by computer collision detection. Workflow is as following (figure4):

Figure 4 workflow

2. 3D RECONSTRUCTION

2.1 Data collection

Different data sources corresponds with different modeling approaches, for example, methods based on remote sensing image and air-born laser scanning are applied to a wide rang of three-dimensional city modeling data obtaining, vehicle-borne digital photogrammetry is applied to corridor area modeling like streets, and ground photogrammetry or close-range laser scanning are used for a single building’ and a few buildings’ modeling. In the case of working object, the major ways to obtain geometrical data are engineering surveying, close-range photogrammetry, close-range laser scanning and blue prints etc.

2.1.1 Surveying: For a large number of relatively regular wooden components, traditional surveying approaches can meet the requirements. In this tache, coplanarity of four points (or