Development of Front End Processor That Provides Midair Sketch Recognition Service for 3D CAD Applications

当这项研究开始时，我们已经建立了一个基于手绘草图的建模接口Blue Grotto，利用虚拟现实（VR）环境，这项研究的目的是建立一个机制，使Blue Grotto作为一个字体端处理器（EP）。作为研究的结果，我们实现了为3D CAD应用提供空中草图识别服务的Blue Grotto FEP，我们确认了Blue Grotto FEP与现有CAD的结合，系统工作得很好，第一步，我们在Blue Grotto中引入了蒙皮操作，并建立了一个新的用户界面，用户可以通过手绘输入多个轮廓。第二步，我们设计了一个通用的通信协议之间的模糊洞穴和实际的CAD应用程序。然后，第三步，对Blue Grotto的视觉反馈系统进行了改造，提高了界面的可用性;第四步，用C++实现了新的用户界面和通信协议第五步实现了两种实用CAD系统的接口模块（AutoCAD和Shade）的通信协议。步骤6通过一些实验性的尝试，我们证实，所提出的通用通信机制使相同的Blue Grotto FEP与不同的实际CAD应用程序协同工作。7通过实际绘图实验，证明了Blue Grotto FEP与实际CAD应用程序的结合可以作为一个基于草图的实用CAD系统，用户可以在Blue Grotto FEP的草图操作和实际CAD系统的命令操作之间自由切换。

When this research started, we had already established a freehand sketch-based modeling interface Blue Grotto that utilizes a virtual reality (VR) environment The aim of this research is to establish a mechanism that makes Blue Grotto serve as a font end processor (EP). As a result of the research, we realized Blue Grotto FEP that provides midair sketch recognition service for 3D CAD applications, and we confirmed that the combinations of Blue Grotto FEP and existing CAD, systems work well as practical sketch--based CAD applications.Step 1We introduced a skinning operation into Blue Grotto and established a new user interface with which a user can input multiple profiles by freehand drawing.Step 2We designed a versatile communication protocol between Blur Grotto and practical CAD applications. Then, we confirmed that the protocol realizes an automatic synchronizing mechanism in the combinations of Blue Grotto and the CAD applications.Step 3We reconstructed visual feedback systems of Blue Grotto and improved the usability of the interface.Step 4We implemented the new user interface and the communication protocol by using C++ and OpenGL and materialized Blue Grotto FEP.Step 5We materialized interface modules for two kinds of practical CAD systems (which are AutoCAD and Shade) based on the versatile communication protocol.Step 6Through some experimental trials, we confirmed that the proposed versatile communication mechanism made identical Blue Grotto FEP work in cooperation with different practical CAD applications.Step 7Through some practical drawing experiments, we showed that the combinations of Blue Grotto FEP and practical CAD applications can work as practical sketch based CAD systems, with which a user can freely switch between sketch operations of Blue Grotto FEP and command operations of the practical CAD systems.