對複雜物件做快速成型模型所需的曲面之經濟簡單的方法

A Simple and Economic Method for the Surface of Rapid Prototype Model on Complex Object

我們提出修正的座標系統轉換理論來整合在不同的座標系統下所量測的控制點，使這些控制點能夠轉換到共同的座標系統。本方法不需要使用特定的置具來量測物件的座標點，並且可以應付在轉換過程中所使用的基準控制點因著重複量測所產生的誤差問題。其做法乃是在每一個分段量測的曲面上取一組4個基準點，並且在連接兩個鄰近的曲面中再重複量測其中的8個基準點。之後再將這兩個曲面轉換到之前8個基準點的座標系統上。我們將此理論應用在人體頭顱和手部模型上。我們使用的工具為RHINO和MicroScribe G2數位化儀。在建模的過程中我們使用放樣法和曲線網線法。由於在建構頭顱模型過程中，在眉骨取點的時候較為粗糙所以產生了模型較像男性，而實際的模型卻是女性的瑕疵。除了上述的瑕疵其餘的曲面與原始模型非常相像。我們並且使用射出成型機將模型用薄殼方式產生。

We propose a modified coordinate system to integrate the measured points from different coordinate systems. This method needs not to use special fixture to take the coordinate of measured objects and is capable to handle the repeated measurement error due to the transformation of basic control points. The methodology is to take 4 basic control points in each measured surface section and repeat measuring the 8 basic control points in the neighboring surfaces. Then transform the two surfaces to the coordinate system whereby the 8 basic control points are taken. We apply this theorem to the artifact of human skull and human hand. The tools used are Rhino and Microscribe G2 digitizer. We use Lofting and Curve Network in Rhino to make surface. Due to the coarse measurement on the eye-bow bone in the human skull, it generates a defect that the surface model looks like male instead of female which indeed is the reality of the artifact. Except to the aforementioned defect the other part of the human skull surface model is pretty much like its artifact. We also use offset shelling to produce the RP object using the RP machine.