法線方向

曲線 - 在曲線上顯示的是曲線的方向，曲線的方向是指起點至終點的方向。

For surfaces the normal is a direction that points toward what you can think of as "outside" or "up." For closed polysurface (cone, cylinder, box, etc.) or single-surface solids (sphere, torus), the normal always points "out." However, on an open surface or polysurface, the direction of the normal depends on how it was created and can seem arbitrary. The Dir command displays an object's normal direction.

實體 (1)、曲面 (2)、曲線 (3)、網格 (4)。

如果曲面的法線方向被反轉，會有藍色的直線指出曲面原生的法線方向。

曲面的法線方向 (左) 與原生的法線方向 (右)。

U and v directions

Every surface is roughly rectangular. Surfaces have three directions, u, v, and normal. You can display the u and v directions and the normal direction with the Dir command.

The u and v directions are like the weave of cloth or screen. The u-direction is indicated by the red arrow, and the v direction is indicated by the green arrow. The normal direction is indicated by the white arrow. You can think of u, v, and normal directions as corresponding to the x, y, and z of the surface.

曲面上的貼圖對應與插入節點都與 U、V 方向有關。

圓形的曲面就像一張捲成圓筒狀的紙張，但開放的兩個邊緣各匯集成一個點。