About Clipping Witness Lines
When editing witness lines, you can clip them using the witness line clipping dragger. To specify a clipping reference, hold down the SHIFT key while you are moving the witness line clipping dragger and select a reference.
Witness lines are automatically updated if the position of the selected reference changes. For linear dimensions, select a clipping reference that projects to a point or line with respect to the drawing view orientation. For angular dimensions, select a clipping reference that projects to a point, line, or an arc centered on the vertex of the dimension with respect to the drawing view orientation.
As clipping references for witness lines are cosmetic, such references that you create in a 3D model are ignored when the associated dimension is shown in a drawing. You can specify a new clipping reference for the dimension after it is shown in the drawing.
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When you select a dimension that has been previously clipped to a geometry reference, the dragger associated with the clipped reference is displayed as a snapped clipping dragger (). This helps you identify whether the dimension has already been clipped or not.
If you have previously clipped a dimension witness line using the SHIFT key, you must hold down the SHIFT key to move the witness line dragger away from the selected geometry reference. In this case to restore the unclipped dragger () for the dimension witness line, move the witness line dragger by holding down the SHIFT key and release the key at a different location without selecting any clipping reference.