底图约束

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描述

底图工作台工具中,您可以通过指针单击3D视图来拾取图形中的点、距离、半径与角度。

但是,当这些参数需要特别精准时,可能就要在工具对话框中输入准确的草图坐标

选择更加精准点的另一种方式是:在X、Y或Z的某一特定方向上对指针的移动加以约束。

水平约束与垂直约束

通过约束点在垂直方向上的位置而创建的垂线

按住Shift键,即可在上一个输入点的水平(X)方向或垂直(Y)方向上绘制当前输入点。至于约束的是水平方向还是垂直方向,则取决于按下 Shift时鼠标指针的位置;如果按键时指针位于上一个点的东西两侧,则约束的是水平方向;如果按键时指针位于上一个点的南北两侧,则约束的是垂直方向。如果要改变约束方向,只需松开Shift键,并将指针移到另一个新位置,再重新按下Shift键即可。

Some tools like Draft Offset and Draft Trimex use constraining differently. They do not constrain vertically or horizontally but use a different method more adapted to the particular tool, for example, constraining the operation to a certain line segment.

While constraining the movement of the pointer, the Taskview panel will lock the coordinate values that are not being modified. For example, if using a horizontal constraint, only the X value changes, while the Y and Z values remain at their original relative or absolute coordinates, depending on whether relative mode is active or not.

File:Draft Constrain Shift Taskview example.png

Taskview when using a horizontal constraint while holding the Shift key

X, Y, Z constraints

Press one of the X, Y or Z keys after a point to constrain the next point on the specified X, Y, or Z direction. Press the same key again to release the constraint.

Pressing X or Y is equivalent to holding Shift and constraining horizontally or vertically, respectively.

Taskview when using a vertical constraint after pressing the Y key