now select the other shapes (triangle and small shapes in the center) (pic 11) and then extrude them to -0.5 of -z axis (pic 12). remember : to extrude a curve as nurbs, open your extrude option box and set the style to distance, and make sure output geometry has been set to nurbs

現在選擇其它曲線 ( 三角形和中心那些小圓 )(pic 11), 然后在 -z 軸上 extrude -0.5 的距離 .
記住 : extrude 出來是應該椒 nurbs 曲面，打開你的 extrude 選項，設定距離并確定輸出的幾何體為 nurbs 曲面 .

before entering this fillet & trim work, there is something important that we should know about preview resolution (antialias settings) and tessellation smoothness within maya.

在進入 fillet 及 trim 的工作之前，有一些很重要的事情我們應該了解一下 maya 的鑲嵌的圓滑設置 .

most of new maya users are shy of this nurbs gaps that are caused by fillet & trim works.

很多的使用 maya 的人都會造成此類現象。