以位移貼圖表示之多邊形網格的剪貼運算

Abstract

我們研發了一個利用彈性表面在使用位置貼圖表示的多邊形上作剪貼的方法。為了能夠在兩個網格之間轉移細節資料，我們必需先找出兩個網格的上面區域之間的對應。傳統方法使用參數化的方式來得到這個對應。我們使用了一種創新利用彈性表面來找到區域之間的對應的方法。彈性表面可以形變以貼合網格，這就如同是建立了一個二維到三維之間的對應。我們利用同一個彈性表面當作中間媒介，分別形變到兩個網格，建立了兩種二維到三維之間的對應。同時，我們因為是用同一個彈性網格，所以我們等同也建立了兩個三維空間之間的對應。有了這個對應，我們就可以在兩個網格區域中複製與貼上資料。我們同時也建立了形變測量方法來處理因為彈性表面所造成的細節形變。

We develop a method to do the copy and paste on polygonal models represented by using displacement map. In order to copy and paste a region of surface detail from one mesh to another, we need to create a one to one mapping between two regions of interest on the source and target base mesh. Previous methods focus on the cut and paste between polygonal meshes and most of them using the parameterization method. In this thesis work, we provide a novel method that define the one-to one mapping between two ROIs by deforming a flexible surface to match the source ROI and to target ROI respec. In this way, we obtain a one-to-one mapping from the source ROI to the flexible surface and another one-to-one mapping from the target ROI to the flexible surface, and here can define a one-to-one mapping between the source and target ROIs. We can not create the one-to-one mapping if the flexible surface not fit on mesh. We provide a subdivision method for the part of flexible surface which is not fit on mesh. Our subdivision method also measure the distortion during subdivision. After the one-to-one mapping is created, we can copy and pate the ROI detail.