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Need help Exporting from VWX to DWG


s1mu

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Thanks@michaelk  

 

That DWG I uploaded was one I converted from a PDF in Illustrator. It has a lot of unnecessary lines and shapes. 

 

I attached the .vwx file that I have. I wonder if exporting directly from Vectorworks to DWG will result in a cleaner file that is better for me to use. 

 

Let me know if thats possible. 

 

Edited by s1mu
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Just a open and resave as DWG will may give a cleaner file or it may not, as it depends on the original drawing.

 

When it comes to converting PDF's to DWG with Illustrator (and similar programs)  it will often create polylines/splines with lots of vertices, you may want to use a dedicated PDF to DWG converter (either as a standalone program, add-on or online service) to see if that gives better results.

 

I don't know how familiar you are with AutoCAD (or any other DWG based CAD program) but there is the "overkill" command which will get rid of duplicates/overlapping lines.

Vectorworks has a similar command, but since you don't have that I'd try first in your CAD program to see if that helps. If you want to do more there are add-on programs for AutoCAD and some of the DWG compatibles that can help in reducing vertices and other things, Dotsoft's ToolPac and DesignSense's CADPower are two of such add-ons to look at that have tools to further clean up DWG drawings.

 

Attached are DWG files as exported from Vectorworks, one is the 2D top/plan view and two others are a 3D view. Some objects are 2D "screen plane" items (groups) that didn't move properly with the 3D View so I have created a 3D v2 file where this was fixed, though it does cause the drawing to have more lines so you  can choose which version you would like to start with depending on the content you want to keep.

7 de Enero LA VISPERA 2D v2020.dwg 7 de Enero LA VISPERA 3D v2020.dwg 7 de Enero LA VISPERA 3D v2 v2020.dwg

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  • 4 weeks later...
On 1/10/2020 at 6:29 PM, Art V said:

When it comes to converting PDF's to DWG with Illustrator (and similar programs)  it will often create polylines/splines with lots of vertices, you may want to use a dedicated PDF to DWG converter (either as a standalone program, add-on or online service) to see if that gives better results.

 

I don't know how familiar you are with AutoCAD (or any other DWG based CAD program) but there is the "overkill" command which will get rid of duplicates/overlapping lines.

Vectorworks has a similar command, but since you don't have that I'd try first in your CAD program to see if that helps. If you want to do more there are add-on programs for AutoCAD and some of the DWG compatibles that can help in reducing vertices and other things, Dotsoft's ToolPac and DesignSense's CADPower are two of such add-ons to look at that have tools to further clean up DWG drawings.

 

 I feel like this should perhaps be it's own thread, but problem is primarily AutoCAD failing to interpret VW 2D line objects (if not, VW failing to convert them properly...), and it also happens that I am also working on an arch...

 

The specifics: I want to export 2d objects to DXF. I have some parts that I would like to have cut on my neighbor's CNC, which is running WoodWOP. His typical workflow involves drawing his parts in AutoCAD, then converting the DXF files to Homag's .MPR format using another program that adds on all the g-code and tooling parameters. I sent him a DXF export of the parts, which include a polyline that containts many bezier curves, fillets, as well as circles and 2d Loci. I tried exporting in all the DWG and DXF versions, but it always converts the polylines to "splines" which has the faceted problem (Neither of us knows what a spline is, but I am guessing it is what VW calls polygons). This is problematic especially for CNC, which requires that angles be outside the radius of the tool path. I had this issue with the complex line, but oddly I also was unable to get AutoCAD to register the circles as DWG/DXF circles - they apparently generated a group of arcs, instead. This problem was solved by adding the locus point, which serves as a drill center rather than forcing the circles convert accurately (the locus becomes the drill center and the arcs are ignored). 

 

I have attached a short clip showing the mouse wheel zooming in and out one click on a 3/16" fillet on an inside corner. I have the display graphics set at Best Performance, and I'm running a fairly capable machine, plus these are 2d objects. I am guessing that when it flickers on and off, it's a glitch in the VGM, but I don't know much about how that works, so it could be something else. Also, it flickers on zoom in TOP/Plan, but is off all the time when viewing the object in the 3d plane (pictured)

 

This could be the same issue when you zoom in on a polyline that is selected, and it shows the orange highlighted object line with facts instead of smooth curves. 

 

Bottom line, though, I don't especially care about the VGM performance (at least in this context), unless it gives me a clue as to why the export module is having trouble accurately converting these lines into compatible geometry in DWG. Does anyone have any ideas about how to workaround this? I was thinking of possibly trying to convert to a different object type, but I figured I would attempt to draw on past experience before jumping down the rabbit hole. Maybe Nurbs or something else? Is it possibly because I have "Flatten 2d graphics" enabled in the export settings?

 

My next step is to try InteriorCAD for exporting this part. Does anyone have experience with using InteriorCAD for custom3D parts/DXF export?

 

 

 

 

image.png

image.png

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A brief update, I went through all of the export settings, and I converted the object to everything that I could try, and the segmentation problem in the DXF persisted, that is until I stumbled across a wiki about how DXF files work, wherein I discovered that the text version of DXF is more robust and accurate than than the binary version. It turns out that was the one setting I don't think I had tried previously, so I went back to my original polyline and exported to DXF text, and wham-o, perfect polyline curves came back. I still have yet to hear if my neighbor's machine is going to bug out again, but I have my fingers crossed. 

 

So my next question is, why would one ever want to export to DXF binary?

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  • 11 months later...

I'm replying to this again, because while it continues to be an issue, I have achieved a bit more clarity about what's happening. Also, I have begun to use InteriorCAD to generate my DXF's, which seems to resolve most of the geometry errors natively within VW that previously came up when directly exporting VW geometry into DXF..

 

In my latest project, I am designing a bed around the client's existing mattress, which has an irregular curvature at the end. I carefully templated the corner radius, then scanned in the template on a flatbed scanner, then traced on the scanned image with a polyline. So far so good. Only, once I convert the polyline to a custom part, it drops the bezier function from the polyline and converts to a series of arcs, instead. This is the original source geometry.

 

image.thumb.png.b8da5fdf9a845e92effa2296f92942ea.png

 

And this is the custom part on top of the same geometry. The yellow wedge that is poking out on the right side is the difference between the two shapes. I have tried several times to fit, but while close, it's not perfect. For this project, it's not so critical with small differences as long as I adjust the surrounding parts to fit the new curve, but in other projects that I've done done recently, when the parts came back from the router, they don't actually fit together as designed, which resulted in a bit of frustration.

 

image.thumb.png.014f5d927b221d89b9d5b4fbcb76a171.png

 

Here you can see that the reshape handles are no longer bezier, but now all arcs:

image.thumb.png.ba3f5e55fcb493f3c559cc1e61f4f16e.png

 

I am assuming that the InteriorCAD algorithm is dropping the bezier due to the lack of universal support for bezier curves in many WOPs? or is it a lack of support in the dxf conversion? I think that my solution will have to be to fit any scanned in curves with arcs rather than beziers, but I am hoping that there is a workaround for this? maybe @Stephan Moenninghoff might be able to shed some light on the underlying principle?

 

Thanks!

 

 

 

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  • Vectorworks, Inc Employee
10 hours ago, mgebel said:

I am assuming that the InteriorCAD algorithm is dropping the bezier due to the lack of universal support for bezier curves in many WOPs?

That's the issue here. CNC equipment expects only arcs and corner vertices. This is the same across the board, from the smallest model-building CNC to large nesting CNCs in the furniture industry. interiorcad automatically converts beziers to arcs when a custom part is created from a curve. If you want higher fidelity, your best strategy is to draw the primitive again, using only arcs and corner vertices.

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3 hours ago, Stephan Moenninghoff said:

That's the issue here. CNC equipment expects only arcs and corner vertices. This is the same across the board, from the smallest model-building CNC to large nesting CNCs in the furniture industry. interiorcad automatically converts beziers to arcs when a custom part is created from a curve. If you want higher fidelity, your best strategy is to draw the primitive again, using only arcs and corner vertices.

 

To be pedantic: radius and corner vertices only. (interiorcad does not support arc vertices)

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  • 1 year later...

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