The process of creating an architectural 3d model in Autocad consists of importing some 2d elevations first, arranging them, then creating closed polylines in order to build 3d objects from those references. We take you through the whole process in our Autocad 3d training courses.
After the 2d elevations and floor plan have been brought into your new drawing we want to create a series of closed polylines that represent the first floor walls, as shown here in the screen shot.
In order to focus on the walls only, turn off some of the other layers: furniture, doors, roof, interior partitions, stairs, railings, and headers, for example. Note that the walls may be simple single lines rather than polylines, and we need closed polylines in order to extrude the shapes upwards in the z-direction. First create a new layer and name it 3D-Walls > change the layer colour to red – something that will make it easy to differentiate the walls from other objects in the scene.
Note that Autocad auto-alphabetizes the layers as well as putting any numbers at the top of the layer stack. You don’t need to follow any particular standard – layers are just for your information.
Next type BO (for Boundary) into the Command line – either a polyline or a region would work for this. Polylines are simpler, but use Regions if the lines include splines. The Pick Points button allows you to click inside a wall area, whereupon it mathematically casts out invisible rays from the click point to detect the closed area. If there are no gaps Autocad creates the closed object. Next type RE to regenerate the drawing – and the walls turn into the layer colour of red.
Type BO again and hit Enter twice; then click in each area. Note – if you pan across the drawing Autocad won’t create the boundary, since the command analyzes what’s actually on the screen. In which case just type BO again (or hit Enter to repeat the command). If there are gaps you’ll get the Cannot be determined message, in which case use the Fillet command to close the corner, and use a radius of zero. Then type RE again to regenerate the drawing if necessary. The objects are now ready to extrude upwards to create the 3 dimensional wall volumes.
The 3d interface in Autocad is user-friendly and easy to learn, and we take time to teach a broad range of applications in our classes including modeling, materials, lighting and animation. See many examples of our clients’ work on our Facebook page. For more information there are lots of resources on the web, but try the Autodesk site to begin with: www.autodesk.com. Support options and user forums are also available from the home page.
Other related Autocad 3d Blog Posts:

• Autocad 3d introduction
• Autocad 3d modeling
• Autocad 3d blocks
• Autocad 3d commands
• Autocad 3d basics