Noob here. Reliable method for importing from AutoCAD?

(TheNCGoalie) #1

Long story short is that I’ve been called on to make an animation of a job we did. All of the engineering was done in AutoCAD. I tried the standard “Import AutoCAD DXF format” plugin, but it only imports lines and poly lines, none of the 3D objects. I’ve tried saving as every variation of the .dxf format but with no luck. Is there a reliable way to import from AutoCAD that includes all objects? I’d really hate to have to re-model everything I already have done, especially as I’m closing in on a deadline. Thanks!

(pauljs75_) #2

Is it possible to export to .STL or .OBJ from the CAD end? Blender should handle those ok. However the exporters associated with most CAD programs don’t produce that nice a mesh. (They’ll render ok with no modifiers, but in some cases they’ll need to be reworked. Lots of loose bits that need to be joined, and lots of tris.)

(Lane) #3

you should try take a look at this:
Im an Autocad user ( i have start with it in the beginning of the 90’s ). I think this guys have done an incredible job.

(chrisd) #4

Thanks for posting that, I will try it sometime soon.

I believe NCGoalie’s issue is that the objects were created using solid modelling tools in AutoCAD. Therefore they are nurbs surfaces, not meshes. I’m using Intellicad (I don’t have AutoCAD), and I don’t know if its possible to convert these internally to meshes. I know Intellicad can export the solids as .SAT (ACIS) files, and these could be meshed in another app.

Lane, do you know if Autocad can tesselate/mesh its surfaces, or is the script you referenced able to do that?

(dgorsman) #5

AutoCAD can convert solids to meshes as well as export various neutral formats, however it typically produces some very large files for meshes, especially if the model has some detail to it. There’s also the problem of how the models were constructed; if they were produced by a vertical product or a third-party tool with custom objects, they’ll need to be converted to conventional solids prior to meshing.

Depending on what the models are, it might make sense to selectively convert objects and re-use those to re-build the model in Blender rather than a full 1:1 conversion where you have to fix almost everything one at a time.

Depending on the licensing available, it might make more sense to walk it through 3DSMAX first, or just do the work in 3DSMAX.

(Lane) #6

As Chrisd was write, you can directly convert a solid to mesh, and then, you have an option called “smooth” meshes, basically it work like a tesselation /subdvision surface.

But, it is needed with AUtocad, to understand, that when working on solid, nearly everything can, and will be made with Bolean operation. ( as with Inventor, Fusion, Revit etc )… This can bring some problem when transforming complex object/solid to mesh.

Many time ago, what i was do, is transfer the objects first in Max, then export them … But looking at the script you can find on my early post. It will be a way more elegant and simple solution.

He explain all, basically, how Autocad differ to Blender with OBJ.

Last night I has got a cough, and start researching blender OBJ open file structure. Blender reads OBJ in other way as other programs does, so I (as LISP coder) found the way to generate an OBJ file, that Blender reads perfectly, directly from Autocad.

(TheNCGoalie) #7

I tried the AutoCAD Lisp script, but it does not work on 3D Solids. The best solution I have found so far is a 30 day trail of 3DS Max so that I can import the .dwg and then export as .obj. This will cover me for the time being while I search for a better solution.

(chrisd) #8

You might also try Moi3d … export a SAT (ACIS out) file from AutoCAD and use Moi to convert to a quad mesh.

(dgorsman) #9

Check your licensing. If you have one of the Suite or Collection licenses, those include 3DSMAX along with a host of other products. Quite a few people don’t realize that.

While you’re looking at options, try FBX (from both AutoCAD and 3DSMAX). I made some progress with it last time I looked at it.

(Richard Culver) #10

There is also Freecad. In can open surface meshes and convert to .obj

(Lane) #11

Create a student account on Autodesk, then you can have free licence ( 3 years ) for any software of Autodesk . No limitation on number of software, they are complete, without limitation, and no watermark. ( and no verification is needed ) ( and as they release a version each year, just choose tthe new version and the 3years is more close to a lifetime one )