How to Attach an External Reference in BricsCAD

Quick answer: XATTACH attaches a drawing as an external reference (Xref), which appears as an insert in the current drawing and can be nested, just like blocks. The attached Xref always reflects the source drawing’s most recently saved version.

Finding the Attach Xref Tool

Any of these:

• The Attach Xref… tool button on the Insert toolbar or the Insert/References ribbon panel.
• Attach Xref… in the Insert menu.
• The Attach Xref tool button on the Details toolbar of the Drawing Explorer’s Xrefs dialog.
• Attach DWG, from the dropdown menu opened by the tool button on the Attachments panel.
• XATTACH directly.

Attaching an External Reference

1. Use any method above; the Select Reference File dialog opens.
2. Select the drawing and click Open; the Attach External Reference dialog appears.
3. The full path to the selected drawing shows in the Path field. Optionally choose a Path Type: Full, Relative, or No path.
4. Choose the External Reference Type:
   • Attachment: if the current drawing is itself attached as an Xref to another drawing, this attachment becomes a nested Xref.
   • Overlay: gets ignored entirely if the drawing it’s attached to is later attached as an Xref to yet another drawing.
5. Choose whether to specify the insertion point on screen or in the X, Y, Z fields.
6. Choose whether to specify the scale on screen or in the X, Y, Z fields; tick Uniform Scale to set it via the X field alone.
7. Choose whether to specify the rotation angle on screen or in the Angle field.
8. Click OK to attach it, then follow whatever prompts your choices in steps 5 through 7 trigger.

Fading, Origin, and Unit Scaling

Parametric external references are also tracked in the Attachments panel for reloading, and reloading one rebuilds all of its inserts, including any parametric ones.

XDWGFADECTL sets how much external references visually fade. The origin point of an Xref is controlled by its own INSBASE variable, set with the BASE command inside that external drawing itself, the same mechanic used for inserted blocks. Likewise, the Unit field under Block Unit reflects the Xref’s own INSUNITS value, and the Factor field expresses the relationship between the Xref’s INSUNITS and the parent drawing’s, the same Unit/Factor logic covered on this hub’s block insertion page.

Frequently Asked Questions

What’s the practical difference between Attachment and Overlay when attaching an Xref? An Attachment becomes a nested Xref if the current drawing is later attached elsewhere itself. An Overlay is ignored entirely in that same scenario.

Does an attached Xref update if I later change the source drawing? Yes, the attached Xref always reflects the source drawing’s most recently saved version.

How do I control how faded an external reference looks? Via the XDWGFADECTL system variable.

Does the Unit/Factor field logic work the same way for Xrefs as it does for blocks? Yes, it’s the identical mechanic: the Unit field reflects the Xref’s own INSUNITS, and the Factor field expresses the relationship between that and the parent drawing’s INSUNITS.