電腦輔助設計實體建模表現與空間能力關係之研究

Abstract

傳統的工程圖學，基於正投影原理，透過平面多視圖描述空間中物體的型態和尺寸；目前工程領域使用的電腦輔助設計（CAD）軟體，則透過實體模型技術直接在電腦裡建立物體的3D模型，等到模型建立之後，系統也能自動產生各種圖形，不必另外繪製。這種以3D模型為主的設計繪圖和溝通方式，具有多種效用和良好的視覺效果，也是同步工程設計的關鍵。由此可知，電腦輔助設計的使用和普及，不僅改變傳統圖形的溝通方式和設計製造的程序，也將改變工程人員的思維。 圖學與視覺化的研究一向密不可分。傳統上，視覺化能力在許多以圖形表達的學科，或需要依賴空間能力的專業領域，具有高度的相關和預測效果。大部分學者也都相信，空間能力可以透過工程圖學的訓練和學習加以改善。由於3D CAD已經成為工程設計的主要媒介，因此，實體模型的使用，是否會影響人們視覺化能力的發展和專業表現？實體建模的構念，是否會改變傳統空間能力的定義、成分和測量方式？值得深入探討。 本研究旨在探討以實體模型為主的3D CAD與圖形溝通和空間視覺化的關係。為達研究目的，採混合設計取向，分成探索與實驗兩階段。研究的探索階段，主要以專家訪談和個案觀察為主，旨在瞭解實體建模的構念；研究的實驗階段，則根據第一階段的研究結果設計教學實驗，旨在探討實體建模與空間視覺化的關係，以及影響實體建模表現的因素。具體來說，本研究主要結論如下：(1)CAD改變傳統圖形溝通的方式；(2)實體建模與傳統工程繪圖的觀念及所需的心理能力已經不同；(3)視覺分割和組合是實體建模的重要構念；(4)實體模型的操弄和學習可以促進視覺化能力的發展；(5)視覺分割和組合是影響實體建模表現的主要因素。

Conventionally, engineering graphics is based on the orthography and presents an real object with the abstract and planr multi-views to describe the shape and dimension. Nowadays, the 3D CAD in the domain of engineering and manufacturing, which is based on the technique of solid modeling, is constructing a 3D virtual model with software directly. While the model was completed, all of the desired graphics will be generated automatically. Due to the excellent visual effect and various availability of 3D solid model, the CAD database also becomes the key factor of concurrent engineering. Therefore, the application and popularity of CAD, not only changing the process of engineering design and manufacture, but also altering the way of graphic communication, as well as the design thinking of engineers. There is an intimate connection between the investigation of graphics and visualization. Traditionally, the ability of visualization is very important and possesses high correlation and predictability in many scientific disciplines which require communication with graphics as well as various professional and technological tasks which rely on spatial ability. Most researchers believed that spatial ability could be improved significantly through the learning and training of engineering graphics. Since 3D CAD is becoming the central media of graphic expression, it is very important to probe whether the definition, components and measurement of traditional spatial ability might required revision or not. This paper is aimed at the investigation of the relationship between the performance of 3D solid modeling and graphic communication as well as spatial visualization. For these purposes, this study adopted a mixed-method approach. The first stage was an exploratory design, which was done mainly by way of interviews with experts and case observation. The findings and results were to be referred to for the instructional experiment in the next step. The second stage was an experimental design of nonequivalent pretest-posttest, which was used to explain the findings of the first stage. Concretely speaking, the conclusions of this paper are as follows: 1) CAD is changing the way of conventional graphic communication; 2) the concept and required mental skills between 3D solid modeling and traditional engineering graphics are totally different; 3) the skill of visual parsing and mental composing are the principal competence of solid modeling; 4) the learning and manipulating of 3D solid model are beneficial to the spatial visualization; and 5) the skill of visual parsing and mental composing are the primary factors that affect the performance of solid modeling.