3D Sketch-Based System for Conceptual Design

这个研究项目的目标是使用户能够检索、修改和重用3D数据，通过简单地绘制手绘草图来创建组件。这将作为一个新的“草图计算”范例的基础。该方法包括：(1)允许用户以手绘草图的形式表达设计思想，同时检测2D草图和3D装配约束。利用相对形状直方图和三维姿态确定从手绘图中检测2D和3D约束。这允许系统捕捉用户的设计意图，而不需要明确的用户规格说明。(2)采用三维模型分割方法，通过局部形状的“剪切”、“粘贴”等操作，方便局部形状的替换和搜索。(3)使用2D和3D约束映射的3D装配技术，然后使用搜索结果进行模型构建。研究目标将使那些没有受过使用复杂计算机辅助设计（CAD）工具训练的人更容易获得设计。这个项目的结果将导致一个可行的基于草图的系统，可能比传统的CAD系统更直观的设计师。这将在设计过程中促进更好的创造力，并减少对用户培训的需要。它还将展示将基于笔的计算集成到许多现有计算机应用程序范例中的新的有用方法。项目网站（http://www.purdue.edu/sketchlab和http://www.purdue.edu/shapelab）将用于传播结果和提供进入实验系统的途径。

The goal of this research project is to empower users to retrieve, modify and reuse 3D data reliably to create assemblies simply by drawing a freehand sketch. This will serve as the foundation for a new "sketching computing" paradigm. The approach consists of (1) allowing users to express design ideas in the form of freehand sketches while detecting 2D sketch and 3D assembly constraints. 2D and 3D constraints are detected from the freehand drawing using relative shape histogram and 3D pose determination. This allows the system to capture the user's design intentions without explicit user specifications. (2) A 3D model segmentation method is used to facilitate partial shape replacement and search through operations such as "cutting," and "pasting" partial shapes. (3) A 3D assembly technique using 2D and 3D constraint mapping is then used to enable model construction from search results. The research goals will make design more accessible for people who are not trained in using complex Computer-Aided Design (CAD) tools. The results of this project will lead to a workable sketch-based system that could be more intuitive for designers than conventional CAD systems. This will promote better creativity during the design process and reduce the need for user training. It will also demonstrate new useful ways to integrate pen-based computing into many existing computer-application paradigms. The project Web site (http://www.purdue.edu/sketchlab and http://www.purdue.edu/shapelab) will be used for dissemination of results and providing access to the experimental system.