TIPniques: Creating 2D Views with Base View
AutoCAD® has been the standard in 2D design drafting for decades. It can also create 3D content, with 3D creation tools that have seen tremendous improvements since AutoCAD 2007. AutoCAD 2010 added mesh tools, the 2011 release added surface creation. AutoCAD 2012 improved on all of these.
AutoCAD 2012 added a new tool called Base View. This tool will (nearly) instantly create two-dimensional views (or isometrics) of your 3D model. Before Base View came along, the process of creating projection or orthogonal views in AutoCAD was tedious and time consuming.
The “Old Way”
Before Base View, users had to use commands/tools such as Flatshot, Live Section, Section Plane, and all of the sectioning tools. Further, users had to manually create different views in order to display them. Once the model and section views were created, the 2D drawings had to be put together in paper space. Different orthogonal views and isometrics were made by creating different viewports, which would create 2D views by displaying the model from a different view. Each viewport had to be manually prepared. Additional viewports would be needed to display the cross sections. If your cross sections were also in model space (along with the main model), then you would need to make sure the model didn’t show in the cross section and make sure the cross section didn’t show up in the model. If you had more than one cross section or model then you were asking for difficulty. Enter Base View.
Base View is one of those golden “nuggets” in AutoCAD 2012 that is often overlooked. AutoCAD users who do not create 3D content ignored it altogether or just brushed it off as a nice tool that they neither could nor would use. But if the reason you haven’t taken advantage of AutoCAD’s 3D creation tool set is because of the cumbersome method of creating drawings from the models, then your excuse has been thwarted with Base View.
To use, start the command by typing VIEWBASE on the command line. In the 3D Modeling workspace, go to the Annotation tab in the ribbon and click on the Base View command in the Drawing Views panel.
Figure 1: Click Base View on the Drawing Views panel in the ribbon to start the Base View command.
TIP: If you are in model space when you start Base View, it won’t work. AutoCAD will alert you. Just go to a paper space tab and start over. You don’t need to activate a viewport because Base View doesn’t use them for view creation. Instead, the software will create a Drawing View object—not lines, circles, solid, or mesh.
Now start the command. AutoCAD will display a drawing view object of your model. Pick where you want this object to be placed. Don’t worry about putting it in the wrong place because you can move it later. In fact, most (but not all) basic modification commands work on a Drawing View object.
Once the first, or Parent, view is placed you will be prompted to place other views. As you move your cursor around, AutoCAD will create a preview of the new view. By default, Base View is set to create third-angle projections; however, you can change that to first-angle projections by clicking on the expansion arrow (see Figure 2).
Figure 2: The Drafting Standard window controls the type of projection created, preview display, and thread styles.
If you aren’t sure which projection type you want to use, or the difference, here is a link to a Wikipedia article on engineering drawings that describes what the view types are. In third-angle view, the base (parent) view will be drawn as the Front view. Above that will be the Top, to the right will be the Right view, and so on. You can also create auxiliary views by moving your cursor diagonally away from the parent view. AutoCAD will use one of the isometric views. Once you have set the views, press ENTER until you exit out of your command. The process of setting up your views is much quicker than to create three viewports, move them, size them, and change the view types accordingly.
Edit Drawing Views
Once the views have been placed, you may want to change some things about them. Select a view. There is one grip in the center of the view. Click it to move the view object. The view will stay in alignment of the parent view. You can use the move command and this can break your alignment. Or, select the view, hover over the grip to get four options: stretch (which will move the view), rotate, break alignment, or repair alignment. Stretch will move the view and keep it in alignment. Rotate, as expected, will rotate the view. Break alignment will break the associativity the view has with the parent view and allow you to use the stretch option to move it so that the view is no longer in line with the parent view. Restore alignment will fix things, unless the view has been rotated.
The Edit View command (also in the Drawing Views panel – see Figure 1) allows you to change view properties. Start the command and select the view you want to alter. You can change the scale, style, and visibility. The representation option will display alternate representations of your model if it was imported from another design program such as Autodesk Inventor®. You can also move the view.
Create More Views
If you want to add more views, use the Projected View command (also in the Drawing Views panel – see Figure 1). Start the command, select the parent view, then place the new view. You can select any existing view to be the parent view.
What if My Model Changes?
If your model changes, AutoCAD will provide a balloon notification and highlight the affected drawing views with red markers (see Figure 3). Click the “Update All Views” prompt in the notification to update the views. You can also use the Update View command or the Update All Views command (also in the Drawing Views panel – see Figure 1).
Figure 3: Drawing Views are easily updated when the model is changed.
AutoCAD 2012 gave us the Base View (VIEWBASE) command to help us generate 2D views of 3D objects. It can create these views quickly and with little effort. The views created are single objects, but users can work with the linework inside them. Creating projection views and isometric views is simple and can be accomplished with a few clicks and without the need of viewport creation or management.