Extract 2D Elements Used to Create 3D Model?

[adt2]

Hi, folks - long-time lurker, first-time poster here.

 

I've recently been given a *.dwg file that seems to contain a 3D model composed of blocks. I'm a long-time SolidWorks user, and in my parlance, what I've got is an assembly composed of individual parts.

 

I need to create a 2D version of each 3D part. Currently, my process is

1. Cut & paste 3D component into new document.
   
2. Select all and perform 'flatten,' removing hidden lines.
   
3. Select all and explode.
   
4. Manually remove a zillion duplicate and unnecessary line segments.
   
5. Manually fix radiused / filleted corners, which have become a bunch of little straight line segments.
   
6. Draw a polyline around the whole part.
   
7. Run 'boundary' to create a new polyline approximating the original shape.
   

 

Clearly, this is not very efficient - nor does it produce an exact 2D duplicate of the face of the 3D part; what I get is a close approximation. I don't use AutoCAD to do 3D work, but I assume that, much like SolidWorks, a 2D sketch is created first and then extruded into the 3D objects.

 

This, in turn, leads me to believe that there ought to be a way to extract that 2D sketch intact for use elsewhere. How should I go about doing this?

 

Thanks in advance for your help.

[kencaz]

Try "flatshot" and or "sectionplane"

 

KC

[adt2]

Thanks for the tip. When I tried "flatshot," I got an error message saying, "There are no solids or surfaces that can be projected." When I select all and bring up the properties inspector, it says "Polyface Mesh," if that helps (or hurts).

 

I tried sectionplane and couldn't make it work (I'll have to spend a few minutes figuring out how the command is supposed to work before I rule it out, though).

[nestly]

I believe AutoCAD2008 has FLATSHOT, that's definitly your easiest and most accurate solution. Also available are the older SOLVIEW, SOLDRAW and SOLPROF but FLATSHOT coupled with OVERKILL to clean up overlapping and fragmented lines is pretty sweet.

[Cad64]

If the objects are in fact meshes, not solids, then I don't think Flatshot is going to work. And for that matter, neither will Solview, Soldraw or Solprof. It sounds like you've just got a collection of surfaces that are all stuffed together inside of blocks. Not a very efficient way of modeling.

[adt2]

Yeah, there's pretty much nothing about this project that I would've done the way it'd been done when it was handed to me - but I'm the one who's got to deal with it now. Any recommendations for dealing with the document the way it stands?

[kencaz]

Try this link

 

http://www.cadtutor.net/forum/showthread.php?59970-A-way-to-quot-slice-quot-a-Polyface-Mesh

[nestly]

I don't know for sure if it's available in 2008, but I think MESHSMOOTH will create a 3D Mesh that FLATSHOT will project. If not, MESHSMOOTH followed by CONVTOSOLID will.

[SLW210]

Post a portion of the file.

[adt2]

3D_Upload.dwg

 

Sorry...took me two days to figure out how to a) make an attachment and b) make it small enough to actually attach.

 

MESHSMOOTH in AutoCAD 2011 sort of worked...I got a warning/error about not creating smooth solids or something, and then it did its thing. FLATSHOT then seemed to work, but it didn't leave me with just the outline of my part - it left all (well, most) of the interior lines in place, which means I'm back to exploding and manually removing the little line segments, and probably recreating the fillets again.

 

How is a "Polyface Mesh" created? Surely there's a way to backtrack and get the original geometry?

[SLW210]

[ATTACH]28510[/ATTACH]How is a "Polyface Mesh" created? Surely there's a way to backtrack and get the original geometry?

 

One might be able to use Inventor or Mechanical to convert back to a solid. I got no warning, but MESHSMOOTH worked here also.

[adt2]

You don't get a warning to the effect of, "One or more of the objects in the selection set is not a 3D object. What do you want to do?" when selecting objects for the MESHSMOOTH command?

 

Re: Inventor - I have a trial version of Inventor installed, but I am unfamiliar with its use. How would I go about using it to attack this problem?

[JD Mather]

Re: Inventor - I have a trial version of Inventor installed, but I am unfamiliar with its use. How would I go about using it to attack this problem?

 

Construction Environment in Inventor 2011 or earlier.

Repair or Construction Environments in Inventor 2012.

 

http://au.autodesk.com/?nd=class&session_id=3056

[adt2]

Okay, I somehow managed to import a single Polyface Mesh into Inventor as a 3D solid. Although I can't see them (everything is the same color), I can tell that all of the line segments are still there because they highlight when I pass the cursor over them.

 

What do I do with it now? How do I extract a 2D *.dwg file of the 3D part?

[JD Mather]

Okay, I somehow managed to import a single Polyface Mesh into Inventor as a 3D solid. Although I can't see them (everything is the same color), I can tell that all of the line segments are still there because they highlight when I pass the cursor over them.

 

What do I do with it now? How do I extract a 2D *.dwg file of the 3D part?

 

You could change the colors of faces, features or bodies same as in SolidWorks (I repaired it as a multi-body solid).

The original file is garbage created by someone who does not know how to use a CAD program. I would use this one only are reference to recreate (without the faced faces).

There is at least one face that is not even horizontal (see attached) but sure looks to me like it should be.

 

To create 2D dwg in Inventor do it just like SolidWorks.

Start a new dwg file in Inventor and place the views. (you can use dwg or idw (think slddrw) template for drawings)

[adt2]

Actually, I don't care anything about creating drawings. What I'm trying to do is get individual 2D part files for each part in the assembly, suitable for use with a CNC machine. The piece you highlight above is an oddity in the file and I probably should've deleted it; the remaining parts are all going to the machinist, though, to be made into patterns for actual production in the real world. The guy who originally drew all of this decided to get fancy and model it, when all we needed was flat, 2D representations of each component so the CNC shop could use the component files to produce patterns for us.

 

The view above is looking down on the assembly (keel and ribs for a 28' boat). What I am trying to do is get a flat, 2D representation of each rib (the long part going from left to right near the top of the view above) from the front (rotate the view above straight back 90 degrees), and a flat, 2D representation of the keel (the long part going from top bottom in the view) as viewed from the side (rotate the view 90 degrees straight back, and then 90 degrees left or right). I don't care anything about any of the 'depth' information; it's useless to me and everyone else involved.

[JD Mather]

These parts are so trivially simple that I would dimension the drawing views, print out and then go back to AutoCAD (or Inventor) and redraw them (2D) without facets.

Done.

About 1/2 hour of work.

[adt2]

These parts are so trivially simple that I would dimension the drawing views, print out and then go back to AutoCAD (or Inventor) and redraw them (2D) without facets.

Done.

About 1/2 hour of work.

 

You left part of your sentence off: "About 1/2 hour of work...x about 100 parts, equals about 50 hours of labor spent duplicating effort that's already been done." I appreciate the input, but hopefully you're on salary somewhere and not charging clients by the hour.

 

For what it's worth, I may have found a workflow that solves my problem. By saving a component to its own file, then importing to Inventor and re-exporting, then running flatshot, I end up with a block reference that's an exact duplicate of the original part (only in 2D). My client is running a sample file past his CNC guy to see if that does the trick; if so, I'm off and running.

[nestly]

Flatshot is a really useful tool, I'm glad you figured out a way to make use of it.

[adt2]

Thanks, me too. I was really dreading having to re-draw all this stuff that had already been done (the sample file I uploaded above is about 15% of the actual file - there are literally a hundred or more parts that need to be drawn).