InterpCrv

InterpCrv 指令可建立一條通過指定點的曲線。

附註：許多 CAD 程式以雲形線 (Spline) 稱呼內插點曲線。

步驟

指定曲線的起點。

指定下幾個點。

按 Enter 完成曲線。

指令行選項

自動封閉

當滑鼠游標靠近曲線起點時自動封閉曲線。

AutoClose steps

建立曲線時移動滑鼠游標至曲線的起點附近，按滑鼠左鍵。

曲線會自動封閉。

按住 Alt 可以暫時停用自動封閉功能。Alt 鍵

Degree

設定曲線或曲面的階數。

建立階數較高的曲線時，控制點的數目必需比階數大 1 或以上，得到的曲線的階數才會是設定的階數。

節點

Determines how an interpolated curve is parameterized. When the spacing between the picked points is equal for the whole curve, all three parameterizations generate the same curve.

When you draw an interpolated curve, the points you pick are converted into knot values on the curve. The parameterization means how the intervals between knots are chosen.

一致

The knot spacing is always 1 and is not based on the physical spacing of the points. Uniform parameterization can be used if the point spacing is roughly equal and it is desirable to draw several curves that have the same parameterization. This is possible only with uniform curves (unless you rebuild the curves). Uniform guarantees that every control point affects the surface exactly the same way, no matter how much the surface is edited.

弦長

以內插點之間的距離做為節點的參數間距，當曲線插入點的距離差異非常大時，以弦長參數化建立的曲線會比一致的參數化好。

弦長平方根

以內插點之間的距離的平方根做為節點的參數間距。

持續封閉

The PersistentClose option closes the curve as soon as there are two points placed.

Note: If you continue to pick points, the curve updates the shape while remaining closed.

起點正切

畫出一條起點與其它曲線或指定的方向正切的曲線。