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QuickDraw 3D, or QD3D for short, is a 3D graphics API developed by Apple Inc. (then Apple Computer, Inc.) starting in 1995, originally for their Macintosh computers, but delivered as a cross-platform system. QD3D was separated into two layers. A lower level system known as RAVE (Rendering Acceleration Virtual Engine) provided a hardware abstraction layer with functionality similar to Direct3D or cut-down versions of OpenGL like MiniGL. On top of this was an object-oriented scene graph system, QD3D proper, which handled model loading and manipulation at a level similar to OpenGL++.〔http://legacy.macnn.com/thereview/features/covert/covert10.2.shtml〕 The system also supplied a number of high-level utilities for file format conversion, and a standard viewer application for the Mac OS. QD3D had little impact in the computer market, both as a result of Apple's beleaguered position in the mid-1990s, as well as several fateful decisions made by the design team about future changes in the 3D hardware market that did not come true. Apple abandoned work on QD3D after Steve Jobs took over in 1998, and announced that future 3D support on Mac OS would be based on OpenGL. ==OpenGL in the 1990s== The canonical 3D API of the 1990s was OpenGL. This had been written by SGI and initially closely matched the capabilities of their workstation systems, operating as a hardware abstraction layer. The OpenGL API consisted mostly of state-setting instructions for setting up drawing modes like the paint color or camera position, and system for sending geometry into the system, normally as meshes of triangles. The combination of these instructions was saved into a display list which was then rendered to produce the output. OpenGL lacked many features that are needed to produce a complete 3D program. Saving and loading geometery data, collecting that data into groups to produce model objects, and the control of state was all left to the programmer. This was considered to be an advantage in an era when performance was limited and direct control over these sorts of functions was a route to improved performance. However, this lack of high-level functionality did make it more difficult to quickly write simple programs, as well as leading to a lack of interoperability. A number of efforts started to provide standardized higher level APIs, like OpenGL++ and (later) Fahrenheit, which handled many of the more common bookkeeping tasks like loading geometry from files and providing a display. These standardized scene graph systems meant the programmer only had to provide the GUI for the program. While OpenGL is mostly low-level, it did include some higher-level concepts that were only really used on SGI systems. This led to another series of APIs that removed these features to make it easier to implement on common hardware. The best known of these is MiniGL, which is not a separate API, but simply a list of those functions in OpenGL that are guaranteed to be supported across all hardware, thus ensuring that a program limiting itself to those calls will run with maximum performance. 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「QuickDraw 3D」の詳細全文を読む スポンサード リンク
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