Join Paul F. Aubin for an in-depth discussion in this video Linking AutoCAD DWG files, part of Revit 2020: Essential Training for Architecture (Metric).
you'll need to access files that are created in other formats. Now the most popular format for architectural files is AutoCAD's DWG, but there are plenty of different formats that are supported by Revit. We've got AutoCAD, we've got MicroStation SketchUp files. So in this video I'd like to show you the most common way or the sort of best practice, there are several different link buttons over here, and what a link is is it's a simply a connection to the actual file on your hard drive.
So, the advantage of that is if the original file changes, you'll be able to just simply reload that link and it will pull in the latest changes. So we're going to use the Link CAD button here, and that will bring up a browse window, and don't double click the file, I want you to single click this file here called AutoCAD Floorplan, because that will allow us to talk about a few of the options down at the bottom. Now I'm going to accept most of the defaults down there, but there are a few that I want to point out. Colors is set to Preserve by default, and there are a few other choices.
I like to choose Invert because as you can see here in the preview AutoCAD is on a black background and the colors are usually optimized for that background, because Revit is on a white background, inverting the colors usually makes them a little more legible. The other setting I want to talk about is the current view only setting. Now if you look in the background in my project browser, we're currently in level one floor plan. If I leave this unchecked, this file will show in any view even though I was in level one floor plan when I added it.
If I check this box, then it will only appear in level one floor plan and not anywhere else. So a way to think of that, and to phrase it in Revit terminology is to say that current view only makes it view specific information, like text, dimensions, or drafting, and un-checking it makes it model information, like walls, doors and windows. The things is it would still be 2D flat line work. It would just be like somebody painted it on the ground, and you'd see it in 3D, or you'd see it in section or elevation. So I'm going to choose current view only, because I only want to see it in this level one floor plan.
And let me go ahead and click Open and accept all the rest of the defaults. Now the CAD file will appear sort of in the middle of the screen. The default insertion point was origin origin. So, if you kind of imagine an imaginary line connecting the two elevations across here, and the two elevations across here, that kind of puts you right about here where my cursor is. Well notice that that corresponds to the lower left hand corner of the CAD file. So it's pretty common for CAD users to use lower left hand corner as their origin, and origin origin just simply lines those two points up.
Now, notice that my CAD file is highlighting and I'm able to select it. If you're not able to do that, there are two selection tools that you need to have enabled in order for that to happen. So we can find those just below the Modify tool here on the ribbon. There's a little select drop down, and you'll see there's a series of check boxes. The first check box is Select links. If that is unchecked, you will not be able to select this file. So that prevents you from accidentally selecting link files. Now even if that is checked, if you have Select pinned elements unchecked, you still won't be able to select this file, because if I turn that back on again, you will see there's a little pushpin icon on this file, and when it's pinned, it says it prevents or allows the change of the element position.
So, when an object's pinned, you can't delete it and you can't move it. So what that does is it prevents somebody from accidentally moving this file which you can imagine is not a bad idea for something that's linked in. So when we use the origin origin option for a CAD file, it automatically pins it. Now you are of course welcome to unpin it and move it if necessary, but in this case, I'm going to undo that and keep it pinned, and allow you to snap right between them.
So notice that I'm able to create a couple walls there that are right down the middle of where the so called walls are in the CAD file. Now I'm going to press escape one time, change to a 79 milometer partition next, and kind of do that again with some of the other wall geometry. Now what you're probably noticing is I'm kind of intentionally stopping short of the intersections. If you want to take advantage of that snap to center line feature, my experience is that it's easier to do that if you draw the walls all a little bit too short.
So, I've drawn just a couple of them to illustrate. I'll roll my wheel to zoom in, and now on the Modify tab, I'll use the trim and extend multiple elements tool. Now this tool allows you to pick one boundary edge and then either trim or extend multiple objects to that boundary edge. So I'll choose this wall, and it doesn't matter if you pick the edge of the wall or the center of the wall, you'll get the same result, and then I could say, "Let's extend that one, and that one", and in fact, I could even extend that one, right? So you can just keep extending or trimming elements as necessary.
Now the command stays active until you tell it otherwise, and it's going to keep that boundary edge until you tell it otherwise. Now the way you do that is to just click an empty space. That will reset the boundary. I can pick a new boundary, and now I could extend, extend, and then if I click the lower portion here, I can trim. So it's both a trim and an extend tool. Okay, not one or the other. Click an empty space again to reset. Pick this wall here, and select multiple elements to trim or extend in some cases.
So, let me click the Modify tool and add a couple doors to kind of finish this up, because of course, you can see that I've gone right over the doorways, but we did that because in Revit as you know, the door will cut a hole in the wall. So all I have to do now is come and locate these doors in the locations that are indicated by the CAD file. Now of course, you can use any of the techniques that you have at your disposal to kind of fine tune the positions of those doors to make them match the CAD file a little better, but now that I've drawn just a little bit of geometry, there's enough here that I can kind of show you what the result of this is.
Remember that we chose current view only when we linked in the CAD file. So if I go to another view like the default 3D view, hold down my shift key, drag the wheel and spin this around, you're going to see all of the Revit geometry just fine, but notice that the CAD geometry does not display here. So that's the result of current view only. So you can kind of work in one view, do the tracing, and then you can go fine tune and finish things up in other views, and you're not going to have to hide that CAD file in those other locations. And the reason that that's advantageous is at some point the author of this CAD file might make a change to it at which point you'd want to reload those changes.
So let me just zoom back out a little bit here, and let's look at that process. So let's say they sent me an updated file. I'll go to the Insert tab. I'll click Manage Links. That displays a Manage Links dialog with several tabs. I'll click the CAD Formats tab, and then you'll see the floor plan listed here. Select its name and it will highlight all the way across. That will activate a series of buttons down at the bottom. Now if the new version of the file overwrote the original version, you can just simply click reload, and it will update it in place.
In my case, the new version has a slightly different name. So I'll click Reload From instead, and then I can choose the alternate file, and then click Open, and when we click okay, you'll see the CAD file update with those changes. Now do notice that it does not automatically change the Revit geometry that you built on top. So I would have to select these things and manually adjust them to match the position shown in the updated CAD file, but that work flow is one that you can employ when part of the team is working in AutoCAD or some other CAD software, and you want to be able to incorporate what their doing into your Revit work flow.
- Understanding BIM and the Revit element hierarchy
- Navigating views
- Creating a new project from a template
- Adding walls, doors, and windows
- Adding plumbing fixtures and other components
- Linking AutoCAD DWG files
- Rotating and aligning Revit links
- Working with footprint and extrusion roofs
- Adding openings
- Adding railings
- Creating stacked and curtain walls
- Hiding and isolating objects
- Adding rooms
- Creating schedule views and tags
- Adding text and dimensions
- Creating new families
- Using reference planes, parameters, and constraints
- Plotting and creating a PDF