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Axonometric projection is a type of parallel projection used for creating a pictorial drawing of an object, where the object is rotated along one or more of its axes relative to the plane of projection.〔Gary R. Bertoline et al. (2002) ''Technical Graphics Communication''. McGraw–Hill Professional, 2002. ISBN 0-07-365598-8, p. 330.〕 There are three main types of axonometric projection: ''isometric'', ''dimetric'', and ''trimetric projection''. "Axonometric" means "to measure along axes". Axonometric projection shows an image of an object as viewed from a skew direction in order to reveal more than one side in the same picture. Whereas the term ''orthographic'' is sometimes reserved specifically for depictions of objects where the axis or plane of the object ''is'' parallel with the projection plane,〔 in axonometric projection the plane or axis of the object is always drawn ''not'' parallel to the projection plane. With axonometric projections the scale of distant features is the same as for near features, so such pictures will look distorted, as it is not how our eyes or photography work. This distortion is especially evident if the object to view is mostly composed of rectangular features. Despite this limitation, axonometric projection can be useful for purposes of illustration. == History == The concept of an isometric projection had existed in a rough empirical form for centuries, well before Professor William Farish (1759–1837) of Cambridge University was the first to provide detailed rules for isometric drawing.〔Barclay G. Jones (1986). ''Protecting historic architecture and museum collections from natural disasters''. University of Michigan. ISBN 0-409-90035-4. p. 243.〕〔Charles Edmund Moorhouse (1974). ''Visual messages: graphic communication for senior students''.〕 Farish published his ideas in the 1822 paper "On Isometrical Perspective", in which he recognized the "need for accurate technical working drawings free of optical distortion. This would lead him to formulate isometry. Isometry means "equal measures" because the same scale is used for height, width, and depth".〔J. Krikke (1996). "(A Chinese perspective for cyberspace? )". In: ''International Institute for Asian Studies Newsletter'', 9, Summer 1996.〕 From the middle of the 19th century, according to Jan Krikke (2006)〔 isometry became an "invaluable tool for engineers, and soon thereafter axonometry and isometry were incorporated in the curriculum of architectural training courses in Europe and the U.S. The popular acceptance of axonometry came in the 1920s, when modernist architects from the Bauhaus and De Stijl embraced it".〔 De Stijl architects like Theo van Doesburg used axonometry for their architectural designs, which caused a sensation when exhibited in Paris in 1923".〔 Since the 1920s axonometry, or parallel perspective, has provided an important graphic technique for artists, architects, and engineers. Like linear perspective, axonometry helps depict 3D space on the 2D picture plane. It usually comes as a standard feature of CAD systems and other visual computing tools.〔Jan Krikke (2000). "Axonometry: a matter of perspective". In: ''Computer Graphics and Applications, IEEE'' Jul/Aug 2000. Vol 20 (4), pp. 7–11.〕 According to Jan Krikke (2000)〔 "axonometry originated in China. Its function in Chinese art was similar to linear perspective in European art. Axonometry, and the pictorial grammar that goes with it, has taken on a new significance with the advent of visual computing".〔 File:Optimal-grinding engine model.jpg|Optical-grinding engine model (1822), drawn in 30° isometric perspective〔William Farish (1822) "On Isometrical Perspective". In: ''Cambridge Philosophical Transactions''. 1 (1822).〕 File:Along the River During the Qingming Festival (detail of original).jpg|Detail of the original version of ''Along the River During the Qingming Festival'' attributed to Zhang Zeduan (1085–1145) File:Axonometric example.gif|Example of a dimetric axonometric drawing from a US Patent (1874) File:Bank_of_China_Tower_massing_model.svg|Example of a trimetric projection showing the shape of the Bank of China Tower in Hong Kong. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Axonometric projection」の詳細全文を読む スポンサード リンク
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