Blender as cad cleanup and surface mesh software

Hello everybody,
I am a fresh (newbie) user of blender on suse linux platform.
I would like to use it as a cad cleanup software and maybe to mesh the resulting surface. I have noticed that blender is able to read, among other formats, iges files, but I am curious on its possibilities of cleaning the newly imported geometry. How does it handle duplicate vertices, lines or faces?
Is there a concept of solid/volume that blender knows about it?
Later on I would like to know about its capabilities for surface meshing (or even volume meshing if it is possible).

Thank you,
Dragos

Hi,

Not too sure what you’re trying to achieve (not too sure you do either) but here goes.

I’m not aware of any Blender IGES importer but if you’ve found one then I’d like to hear about it. I import data from Pro/Engineer using the .slp importer and sometimes the .stl format. As for CAD cleanup that’s better done in the parent package. What package are you exporting from and what exactly do you want Blender to do with the import?

Blender has included scripts to clean meshes of things like double vertices, edges etc. but be aware exporting data from solid modelling CAD packages can produce some horrible meshes due to their triangulation routines. Best to run a few tests on models you’re likely to be using. Go into edit mode then run scripts such as “Clean Meshes” or “Remove Doubles” etc.

No, Blender has no concept of solids or volumes, it’s a surface modeller.

Don’t know what you mean about surface meshing or volume meshing. Any imported data will already have a surface mesh.


http://www.digital-air.co.uk/

Blender will make a good job of importing a .stl or .vrml file from a solids modeller. I use Solidworks and had a lot of success with some of my models. As ardee said, the output from the CAD packages will be triangulated and won’t always give you a logical mesh to clean up.

I now find it quicker to do the initial model and assemblies in blender and only commit to solidworks when I am happy with the model. It means remodelling the parts but I find it much easier to recreate something with a defined shape in the CAD package than develop the shape on the fly. Parametric constraints can be great if you know where you are going with a part, but can be a real hindrance if you don’t.

Check out my Engineers Guide, It covers most of what you will need.

I, too would be very interested in an IGES import option. ardee, what is the “slp” format that you’re referring to? Any such alternative geometric data import options are of interest to me.

The W-key menu holds a handy “remove doubles” option which cleans up a mesh nicely (combining all verts within a user-defined distance from one another). Another one that’ll likely help is the CTRL-N (align normals out) command. There used to be a nice tri-to-quad script found in the scripts panel menu, but I’ve been missing it on recent releases.

One more little tip for STL import. Many have complained about having to import multiple-part assemblies one part at a time due to STL export from CAD apps typically being limited to exporting only one part at a time. A workaround is that many CAD apps have a feature/function that will convert an assembly to a single multi-body part. Converting your assembly in this way prior to STL export allows a simple transfer into blender. The one “gotcha” is that blender doesn’t do well with importing large (high-poly/vert-count) meshes. Thus you typically have to “break up” your larger assemblies into several sub-assems prior to generating your STLs. Once imported and “cleaned up” (via removed doubles, etc.) the individual parts can be separated (P-key in mesh edit mode) quite easily if desired. (Usually one only separates those parts that will be moving/animated or to aid in material application.) Also, joining meshes back together isn’t too big of a deal either (J-key? - can’t recall). Hope this is of some help to my fellow CAD jockeys out there.

@mzungu

.slp is a Pro/Engineer Render format that I’ve found gives better output for import into Blender (.slp importer is bundled with Blender). Don’t thing anything but Pro/E will use that format though.


http://www.digital-air.co.uk/