While the term "mask reference" is not a standard AutoCAD term for this specific operation, the process described in the provided reference is how you clip an External Reference (XREF). Clipping an XREF is a fundamental method to control the visibility of referenced drawings or objects within your current drawing. This process allows you to display only a specific portion of the referenced file.
Based on the provided reference, here are the steps to clip an External Reference (XREF) in AutoCAD:
Steps to Clip an External Reference (XREF)
To clip an external reference, you typically select the XREF and then define a boundary. Follow these steps:
- Select the XREF: In your drawing, click on the external reference object that you want to clip.
- Access Clipping Tools: After selecting the XREF, a contextual tab will appear on the ribbon. Click on the External Reference tab. Within this tab, locate the Clipping panel and click on Create Clipping Boundary.
- Address Existing Boundaries (If prompted): If the selected XREF already has a clipping boundary, you will be prompted. Specify yes to delete the existing boundary and define a new one.
- Specify the Clipping Boundary: You need to define the shape of the area you want to keep visible. You have several options for creating the boundary:
- Select a polyline: If you have a closed polyline drawn previously, you can select it to use as the clipping boundary. The polyline must be closed and non-intersecting.
- Specify a rectangular clipping boundary: Draw a rectangle by picking two opposite corner points.
- Specify a polygonal clipping boundary: Draw a multi-sided shape by picking a sequence of points. Finish the polygonal boundary by pressing Enter or C to close it.
Once you've defined the boundary using one of these methods, the XREF will be clipped, and only the content within the specified boundary will be visible.
Understanding Clipping Boundaries
A clipping boundary acts like a window or a frame for your external reference. Anything outside this boundary is hidden from view, while everything inside remains visible.
Here's a quick overview of the boundary types:
| Boundary Type | Description | How to Create |
|---|---|---|
| Rectangular | A four-sided, straight-edged boundary. | Pick two opposite corners. |
| Polygonal | A multi-sided boundary with straight edges. | Pick points to define vertices, close the shape. |
| Select Polyline | Use an existing closed polyline object. | Select the pre-drawn polyline. |
Choosing the appropriate boundary type depends on the shape of the area you need to isolate from the XREF.
Practical Insights
- Deleting Existing Boundaries: The prompt to delete an existing boundary ensures you can redefine the clipped area easily. Saying 'yes' replaces the old boundary with the new one you are about to create.
- Using Polylines: Creating a precise polyline beforehand offers the most flexibility for complex clipping shapes. Ensure the polyline is closed before attempting to use it for clipping.
- Invert Clip: After creating a clip, you can often choose to 'Invert Clip' to hide the area inside the boundary and show everything outside. This can be useful depending on what you need to isolate.
By following these steps, you can effectively clip an External Reference in AutoCAD, controlling exactly which parts of the referenced drawing are displayed in your current file.
