容積同材質不同物件表面重建法的探討

The approach to restruct different object's surface in the same tissue type in volume.

翁健欽(chien-chin Weng)

指導教授 ： 蔡明達

中原大學/工學院/資訊工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100403

摘要

此系統主要是利用一種新的方式來實做Marching Cubes演算法，在本文中稱之為New MC，是為了區別舊系統所使用的方法。
New MC的功能主要是用來重建容積表面，在實做前必須先把容積正規化，分成最細小的單位-樣點（Sample Point），然後再利用New MC判斷這些樣點如何組成繪圖時所使用的基本單位-三角片。
此系統使用New MC並搭配舊系統所使用的法向量計算程式，分別將三角片每一個頂點的法向量求出，再合併三角片頂點本身的座標資訊，然後存入STL的動態陣列之中。
如此一來，可達到下列目的：
l 利用近年來的顯示卡均對Open GL畫三角片做出最佳化處理的優勢，將資料結構修改成以三角片為基本單位，可提高繪圖的速度。
l 將CUBE內三角片可能產生的CASE，預先建立好一個對應的表格MAP，當程式判斷完此CUBE是屬於何種CASE的時候，就可以立刻將三角片畫出，降低出錯的可能性。
l 資料結構使用STL的Vector動態陣列來實做，較易維護，較少出現記憶體出錯的可能性。
l 解決舊系統會產生破洞的情形，並提供更高品質的圖形
l 針對指定的OBJECT，畫出指定的顏色

本系統也承襲了舊系統可以繪畫多組容積的優點，並接受舊系統手術模擬完之後所儲存的資料，將之重繪出來。

關鍵字

容積素 ； 容積 ； 表面重建

並列摘要

This Rendering System was called Volume-Pro Rendering System , which was developed to show the result of surgical system in old Rendering System and make the objects having different colors according to the structure codes .
The new system uses a new approach “New MC” to re-construct the surface boundary .
Before implementing this approach , we must normalize the Volume first and make them become the basic element : sample points .So we could use New MC to judge those sample points to construct the triangles for render scene in OpenGL .
We calculate the normal vector with normal function which was used in the old rendering system ,and the new system recorded these information in STL container .
The STL container record such information : triangles’ positions in the 3D space , the normal vector of triangles .
Now , we can achieve the following goals :
1. Using the latest display card has the ability of utilizing OpenGL in efficient way.
2. The New MC constructs the Volume with 256 cases , and we makes every case has its unique function and unique index code ,we minimize the occurrence of holes.
3. Using STL as the data container makes maintenance of the system easily .
4. Resolving the color mix problem in old system .
5. Suppling high quality image .
This system could be maintained easily because of the data structure using dynamic vector to record all information , the programmer could manipulate them easily .

並列關鍵字

Volume ； Voxel ； Marching-Cubes

參考文獻

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