I’m often asked about the difference between a “sheet” and a “drawing”. Technically they are the same thing. The drawing file created by the SSM is just like any drawing you create using traditional methods. You can draw geometry in model space, create additional layout tabs, etc. The only technical limitation is that sheets in the SSM sheet list can only point to a layout in a drawing file. If you want more than one layout in your drawing, you would have to import those additional layouts into your sheet list. There is no technical reason why you shouldn’t have multiple layouts in your drawing, however the new sheet set paradigm or “best practice” is to have one sheet drawing (DWG file) for each sheet in your set. The main benefit for this is to enable multiple users to work on different sheets at the same time. If you have two sheets that point to different layouts within the same drawing, the drawing file will be locked as soon as one person opens one of those sheets… which is how AutoCAD has always worked.
I wanted to provide a quick overview about how sheet sets are intended to work before we move on to more complex topics.
- Create your model geometry in its own drawing file (DWG). Continue to create model geometry in modelspace… Continue to create xrefs, nested xrefs, etc. In that particular DWG file, focus on nothing but the model… try to forget that the layout tab even exists. From now on, let the “sheet” deal with the layout.
- Create a new sheet. As you know by now, creating a new sheet will create a new drawing file (DWG) with an active layout tab. The sheet name in the sheet list is simply a shortcut to that layout in the DWG file.
- Open the sheet, which is really opening the “sheet” drawing file with the layout active.
- Add resource drawing views to the sheet layout. I’ll talk more about this in an upcoming post. For now, suffice it to say that this is where you create layout viewports and attach the model drawings as xrefs. Using the sheet set paradigm as it was intended, you collect design information from other sources (external references attached in model space) and assemble them into a sheet layout (titleblock, viewports, notes, etc in paper space). The only objects that should exist in model space are attachments to external files.
- Add sheet information to the sheet layout. You might add sheet notes or other sheet (paper space) information that is specific to the sheet. Although you can (technically) draw in model space, create more layouts, etc. The intention is for this particular DWG file to be a single sheet with external references to model drawings.
Does it sound like I’m repeating myself? I guess I am... but I want to be sure you get the point :-). Aside from separating your Model and Layout into two different drawings, the general concepts (xrefs, model space, viewports, layouts) should be familiar to you. Although the process I described isn’t strictly enforced with sheet sets, you should consider how you can transition to this process so that you can take full advantage of Sheet Set functionality.