Clip Mask

To clarify - you have a reference attachment. You would like to mask (hide) part of the attachment, but in the middle of the masked portion, you would like a "window" to show a portion of the reference?

I don't think that can be done. I've never found a way to do it. Whenever I've needed that, I either do some VERY creative shapes for my mask fence, or I just create a secondary copy of the attachment, clipped to just that part I need to show within the mask. I have never found a way to punch a hole in the mask.

To clarify - you have a reference attachment. You would like to mask (hide) part of the attachment, but in the middle of the masked portion, you would like a "window" to show a portion of the reference?

I don't think that can be done. I've never found a way to do it. Whenever I've needed that, I either do some VERY creative shapes for my mask fence, or I just create a secondary copy of the attachment, clipped to just that part I need to show within the mask. I have never found a way to punch a hole in the mask.

I  figured out a way. Created the areas then created a hole from them. Use that to create the fence. 

Opps I was wrong.  Looked back at the file this morning and the clipping did not happened as I thought.  Guess I will have to be "VERY" creative.

Thanks for replying too.

if clip mask will not do what you need maybe you could possibly explain in more detail what you are looking to do and an alternate workflow might be able to be found.

I need to clip a reference file, with areas outside and inside that remain.  The image shows the area to clip in a blue outline, with X's for the inside areas to remain.

Create a filled shape using the background color over anything you want to clip out. You can use Priority settings on levels, reference files or elements in a 2d file to put the filled shape on top of everything. In a 3d file you will need to adjust the elevation of the filled shape to be above anything to be clipped.