I am having trouble importing DXF files into Blender. They appear as a large incomplete circle and a large bunch of lines which is nothing like the building drawn in Autocad. can anybody suggest an easy solution to this problem?
Try to export in DXF 12 or 14 format. AFAIK Blender doesn’t have good support for newer DXF formats. Also, be carefull to what you export. Blender world isn’t unlimited like Autocad (well… is not like Acad world is reallu unlimited, but is Way too big compared to Bender and this causes clipping problems 
), so very likely you want to scale your drawing in autocad, so the limits are in the range 0-10 in both X,Y coordinates.
Also, be warned that 3D solids in autocad aren’t supported in Blender.
The script that exists (for 2.5) works fairly well.
Yet you don’t want to import large drawings, so you can split them in different parts and import them separately and be sure that you explode everything cause some lines aren’t recognized and don’t show up.
What I do is explode several times in autocad and then split my drawing up in facades, cuts, plans…and import them one at a time.
Once 2.6 is finished the script will be better.
By the way this is for 2.5.
greetz
You might also try using http://usa.autodesk.com/adsk/servlet/pc/item?siteID=123112&id=10775855 to convert the file to something like .obj and then import into Blender.
Nice tip Quandtum.
I’m under the impression that this is a standalone converter?
Will try it some time to see if it works better than directly import the DXF.
Aye, it is standalone. I used it more in 2.49b for some import/export scripts that didn’t exist then I do now with 2.55 (most apps have moved to .obj). However even with .obj I’ve had problems with importing to Blender and a simple translation through this tool has in some cases fixed it (regarding material UV’s if I remember right). Just a nice work around to have availiable when it’s needed, not sure if it will work for you here or not, but worth a quick try.
AutoCAD has a function to convert solid entities to .3DS files (or at least it used to, as 3DSOUT command.) This actually made for pretty good blender meshes for a while there… not sure as to the latest status of 3DS support nowadays, tho. If the need is frequent, investing in a good translator, such as Accutrans, will be worth the cash.
Autodesk removed the 3ds support with autocad 2007. Optionally you can download an updated addon that enables the functionality for autocad 2007-2009. exporting solids data to meshes is gone for good since autocad 2010. (All current autodesk products can import DWG formats so is not a big deal from their viewpoint).
Do they still allow export to a solid model format, such as ACIS or parasolid? What about STEP or IGES or STL? If STL is supported (you’d think it would be since the format is so common for 3D printing / stereolithography) then that’s the no-brainer default as Blender’s STL support is very solid (tho workarounds are needed for assemblies when using this format - not usually a big deal, tho.)