Hello,

A little background first. I am somewhat new to 3D modeling (via SketchUp and then OSX Rhino) and have recently purchased MoI for use on OSX. Thus far I'm just thrilled with MoI and its unique interface which makes the modeling process very intuitive--well done Michael! I want to be able to produce 2D construction drawings from my models for shop use so am looking for an inexpensive tool that does that task in concert with models created by MoI. While Rhino could do this, I don't want to use Windows, and the OSX beta has not yet addressed this area.

Initially I looked at DraftSight V1R3.2 (free from Dassault Systèmes), and used the DXF export from the MoI 1-Aug-2013 beta. While the model (attached) showed up, there were artifacts that needed to be cleaned up (curves showing up as polylines for example) and the dimensioning process was cumbersome (though I've only just downloaded the app). One very odd aspect was dimensioning units. Most of the drawing elements showed up with inches as intended, but the pivot hole in the knee seemed to trigger switching to millimeters which I couldn't get to switch back to inches. Summary opinion of DraftSight: too cumbersome for the task at hand, particularly if I have to do a bunch of tinkering each time I import a revised model.

Seeing several references to ViaCAD, I downloaded the trial of the 2D3D version (8.0.3, build 1016). Seeing that it could read the .3dm files from Rhino, I figured that would be the best choice to get a faithful import of the model. Not so much though. I played with the import options and typically would find that two holes were missing, there were extra curves showing up, and many faces were missing (both curved and plane). Oddly there was part of one curved surface that had been deleted in MoI, but showed up in ViaCAD; I opened the .3dm file with OSX Rhino and the curved surface did not show up.

Next I began to run through the other file formats common to both programs hoping to find one that would result in a complete model and be easy to work with. After trying DXF, IGES, SAT, and STEP, I have not found it yet. I'm using ViaCAD's Model to Sheet command to produce the 2D drawings. I don't know if it is a function of the trial copy, but in any of these formats, there is no option to use the Precise method for the Model to Sheet command, only Polylines which results in curves that cannot be dimensioned so I can't even dimension simple holes.

So while I'm babbling about my fumblings with ViaCAD, my real goal is to arrive at a clean process (without a lot of editing) of producing 2D construction drawings from MoI models. It seems as though ViaCAD might be a good tool to do this with, particularly using its Model to Sheet command, but without being able to access the Precise method of translating curves, it seems broken.

Is there a preferred format to use when exporting to ViaCAD?
Do others who have ViaCAD 2D3D v8 see the Precise method available in the Model to Sheet command?
Is there another alternative inexpensive CAD program for OSX to do this task?
Any other pointers or encouragement on how to accomplish this task?

--Larry

Hi Larry, it seems that I've found before that SAT format tends to be the best way to transfer into ViaCAD, with that format it seems to mess around with things the least amount. Some of the other formats it seems to try to "heal" the model which more often seems to mess things up I guess.

Using your posted model, I saved out to SAT format (SAT file attached here) and loaded it into ViaCAD v8.0 Windows version, and I can't seem to see any missing holes or badly formed areas, I get a result like this:



Do you see something significantly different from that with your own import?

One thing I noticed is that hidden objects show up in ViaCAD when you do a "Save As" out from MoI, I hadn't really noticed that before. To avoid that you can select all and then do a File > Export out from MoI rather than a "Save As" - export will only write the selected objects out to the file you pick rather than writing all objects.

If you're getting something significantly different from the above screenshot, you might try using the current MoI v3 beta rather than v2.52 , you can get the current v3 beta from here: http://moi3d.com/beta.htm

> Do others who have ViaCAD 2D3D v8 see the Precise method available in the Model to Sheet command?

Where is it supposed to show up, is it supposed to be right in the "Model To Sheet" dialog? I guess I don't see it there either, maybe it's only available in the "Pro" version. What happens if you create a dimension on the holes before you run model to sheet, does it come through?

Another inexpensive option for drawing generation on Windows is Alibre, but I don't think they have a Mac version unfortunately...

- Michael

Hi Michael,

Thanks for the quick response. A few responses to your thoughts. First, I am using the v3 Aug-1-2013 beta. Second, I get the same display as you show when I Save As SAT from MoI and Import into ViaCAD as ACIS SAT. The model looks to be accurate.

I had been focusing on the solid objects (orange parts), and then running the Model to Sheet command on them before playing with dimensions. Your thought about dimensioning in 3D mode before Model to Sheet prompted me to experiment more. Well, in 3D mode, ViaCAD's dimensioning tools do not allow radius, diameter or center marks to be placed on the circles or arcs of the solid objects. I checked the Snaps and both Center and Curve On were enabled. Seems like ViaCAD doesn't see the centers of these objects.

Since the original MoI model still has the original Closed Curves I used to create surfaces and then extrude into the objects (in black, on the bottom of the orange solids), I tried to get ViaCAD to dimension the circles and arcs there, but it behaves the same way. When I select the circle which became the pivot hole of the knee, ViaCAD identifies this as Control Point Spline_49. Seeing this behavior makes me think there is something fundamental that I'm not understanding. I've been making the assumption that I could create a model in MoI, then import it into another tool and dimension it. But it seems that neither the solids nor the surfaces are producing objects that ViaCAD is recognizing as circles and arcs. I'll have to experiment more tomorrow and read more of the ViaCAD manual...perhaps there is something I need to enable, but that seems odd given that the linear dimensioning tools do work.

At this point it seems that the Precise method of the Model to Sheet command doesn't have much to do with this as I'm struggling with getting the radius or diameters to work even in 3D mode.

--Larry

Hi Larry, so what's probably happening for the circles is that there are a variety of entity types that can be stored in an SAT file, and MoI ends up writing circles as a generic spline entity type.

Meanwhile it appears that ViaCAD will only apply radial dimensions on to circle or arc entity types, and it does not do any automatic conversion to check if any spline curves actually have the shape of an exact circle and convert them to more specialized circle entities if they do.

However, there is a tool in ViaCAD that will convert general spline geometry into more specialized entities, in the Windows version it's on the menu under Edit > Simplify object.

So if you have some circle curves that will not dimension in ViaCAD, try selecting them and run Edit > Simplify object and then they will probably dimension ok after that.

It would be nice if geometry would be automatically simplified just at import time, maybe that's something that you could suggest to the ViaCAD developers to implement.

There is also a setting in MoI that you can edit under the moi.ini file, go to Options > General and push the "Edit .ini file" button, then inside the .ini file set:

[NURBS Export]
WriteAnalyticCurves=y

Then for some file formats (I think maybe IGES and STEP) it will try to create more specialized analytic circle, arc, or line entities rather than general spline entities at export time out from MoI but unfortunately I don't think that is implemented for the SAT part of the file import/export library that is being used.

- Michael

Hi Larry and Michael

I'm using viacad 8 pro, and there is not the option for precises curves. I think it is only a feature of Shark lt or fx. Anyway, in viacad you can set the resolution to super fine, in the inspector window, and the preferences. For the curves, you can use "arcs from curves", it is on the tools palette. It's just a litle work to do, and after that, you can dimension your drawing. I'm using step or iges to export from MOI.

By the way, Moi is a great tool, i use for all sort of work, design, construction drawings, 2d work, with the same ease of use. Great work

Cheers

Following up on this, I tried ViaCAD's Edit > Simplify Object and it does allow some of the circles and arcs to be dimensionable.

The "WriteAnalyticCurves=y" idea sounded interesting, but for IGES and STEP formats. With moujiik's comments about setting resolution and the use of the "Arcs From Curves" tool, and that he uses the IGES and STEP formats, I've got the following recipe that is getting me closer to producing dimensioned drawings:

MoI:
[NURBS Export]
WriteAnalyticCurves=y
Select All, Export as IGES

ViaCAD:
Preferences > Custom Resolution > Resolution: Super Fine
New 3D file
Import IGES export file
Type IGES
Flavor: Generic
Trim Curve Options: Follow File
Auto Heal Bodies checked (have not experimented with turning this off and on)
Select all
Model To Sheet
Method: PolyLines
Use Draw Views checked
One Part Per Sheet checked
Window > Concept Explorer > Layers
Label sheets

Now at least the data is coming through from the MoI model & I can get some basic dimensions onto a construction drawing which is a big step forward. Thanks for the help!!!!

--Larry

In MoI, do a drill down selection to an edge object, then Ctrl+A and Ctrl+C. Hide your objects and Ctrl+V the curves in, then export those to viacad with iges. Dim away....

Looks like the new dxf export does all that for you. So export as dxf, then dim away....

Thanks BurrMan, exporting only edges does simplify the process enormously...ViaCAD sees the underlying circles and arcs right away.

MoI is such an elegant tool, it is almost painful to use to ViaCAD! I'm also finding that I don't get the same results twice when I try to do things the same way again. Probably user error, but ViaCAD seems rather fragile.

--Larry

Hi Michael,
Can you look at the viacad import of this model? Exprort part as sat for a solid, then export part as dxf.

Import both files. The dxf requires choosing "mm" as units to match. Is Viacad not reading something? Or, is your dxf not writing out the units yet?

Could it be related to dxf being somewhat "unitless" and just various things will not translate the same?

Thanks.

Hi Burr,

> Can you look at the viacad import of this model? Exprort part as sat for a solid, then export part as dxf.

Do you mean the model attached to the first post of this thread? The issue is probably that it's set in MoI as "No unit system", and I don't think ViaCAD has an equivalent setting in it for "no unit system" so it probably decides to use some arbitrary default, and the default could be different for different file types.

If you set the units in MoI to one that ViaCAD supports (looks like: inches, feet, mm, cm, m) then it should likely work better.


> Or, is your dxf not writing out the units yet?

MoI does write the units to the DXF file currently, it gets written to a header variable called $INSUNITS which AutoCAD will use as the default settings for inserting the file as a block. It's the closest thing that DXF has to a units setting, and several programs will read a units value from it. I believe ViaCAD reads it from there if you set the option for File Units: "Extract From File" except I guess from what you're describing it won't recognize "no unit system" ($INSUNITS = 0) and will instead decide to use inches in that case I guess.

Let me know if any of that does not seem to make sense.

- Michael

Hi Burr, also re:

> In MoI, do a drill down selection to an edge object, then Ctrl+A and Ctrl+C. Hide your objects and Ctrl+V the
> curves in, then export those to viacad with iges. Dim away....

The 2D export file formats (AI, PDF, and DXF format currently) will automatically write out edges without needing to do any manual duplication of them, just do a "Save As" or "Export" of the solids directly and the edges of the object are what get written out.

Just be aware that you'll get a lot of stacked up duplicated 2D curves, because for example both the top and bottom parts of an extrusion both get written out, it only does a simple wireframe export and not a hidden-line removal one at least not quite yet...

- Michael

Ahhhh. Didnt notice the units set on the file posted in the first thread.. Assumptions....

With the dixf I used the 3d curves, cubic splines export and imported that over the top of the solid so I could dim the solid model up...

Thanks for the help...

This is an interesting topic. I don't have ViaCAD but I have TurboCAD and SolidWorks and I wanted to see what results I would get. TurboCAD would open the native 3dm file but would not dimension the circles and arcs as they were not recognized as such. Same with the SAT file. Although SolidWorks would open the native 3dm file it worked best with the SAT file. SAT import asked for what units the user wanted to assign and would recognize and could dimension everything.

I think it would be great if at some point Michael added the ability to create the dimensioned drawings right in MoI.

Vicad doesn't handle precise curves conversion on model to sheet, this is a feature for shark only, so, arcs and splines are only acquired on model to sheet in shark, on VIACAD you can only get polylines

See description on advance drafting notes

http://www.punchcad.com/c-30-compare-viacad.aspx
http://www.punchcad.com/c-29-compare-shark.aspx

Luis G