3D人物頭部模型風格轉換

Abstract

我們提出了一個基於多階層模型風格轉換的演算法。透過非固定邊界之模型參數化(mesh parameterization)，我們將輸入部份模型網格(patch)投影至U-V空間上，然後再藉由重新網格化(remeshing)把投影至U-V空間的平面網格在影像空間中進行重新取樣，重新取樣後的每個取樣點儲存了其對應至原本三維空間上的位置資訊。另外，我們將三維模形風格分為兩個層面：其中之一我們稱之為基本形狀 (base shape)，另一個稱為細節構件(detail components)，此兩種風格是使用影像空間上的複利葉轉換(Fourier transform)計算所得。我們同時也透過在三維空間上將原本模型減去基本模型來計算細節構件來避免重新網格化至影像空間的過程中所造成的混畳效應(aliasing)。在最終的轉換部份，我們所出的方法可讓使用者自由的加上、取代、或是混合所輸入的來源與目標模型所具有的風格。

In this thesis, we propose a multi-level shape style transfer method. We first apply mesh parameterization to project input patches to U-V domain meshes with free-boundary, and then perform remeshing to re-sample U-V domain meshes to image space. Each vertex in this mesh stores its original 3D position. We split shape style into 2 degrees, the first is called “base shape”, and the other is called “detail components”. Both degrees of style are computed through Fourier transform in image space. We also prevent aliasing problem during remeshing to image space by computing the detail components through subtraction of original patch by reconstructed base shape in 3D space. The final transfer process allows user adding, subtracting, or blending selected styles and transfer to selected source model.