

You can select objects manually, by picking them on screen, or you can use powerful filtering tools to automatically select objects on certain layers. The Objects to Trim section controls what gets trimmed.

You can select an object in the drawing (a closed polyline or circle), or you can define a closed polyline by picking the vertices. The Boundary section controls what object is used to determine which objects are trimmed and where they are trimmed. Both commands are similar but in the post we will focus on the Boundary Trim command. You can find the Boundary Trim and Boundary Break commands on the Tools tab of the ribbon in the Planning and Analysis workspace or by typing the commands MAPTRIM and MAPBREAK respectively. You just need to download and install the AutoCAD Map 3D Toolset. Now that AutoCAD Map 3D is included for free with AutoCAD to anyone on subscription you should take advantage of them. There are two great commands for automating this that are hidden away in AutoCAD Map 3D. At one point or another, we are all faced with the tedious prospect of breaking or trimming a large number of drawing objects on different layers.
