Michael.

Here's a couple of zipped files. One is in .sat format and the other is .step. The .sat file comes into MoI v3 beta a bit mangled, but the .step is OK and perhaps good for the purpose of comparison.

They were both exported from ViaCAD v7 and they both seem to import back in alright.

I don't know if it's a ViaCAD or MoI glitch, but I hope they're of some use in finding the problem.


Cheers.
Martin (2).

Thanks for the test file Martin, I'll take a look and I can probably send that along to the guy who does the SAT import filter. These things unfortuantely can often be pretty complex to investigate though so I would not really expect any super quick action on it.

Thanks,
- Michael

The model wasnt stitched properly. The step opens in Viacad corrupt:



I import the SAT file into Viacad and get an object type of "mesh" and once also "surfaces" with visible gaps.

Be sure object type is "solids" then run "stitch from modify-solid utilities menu, then re-export sat and it opens ok.

Michael.

Thanks for taking the time to look - I hope the .sat file is of some use, but I've just seen what BurrMan has written about the .step being corrupt too.


BurrMan.

I didn't notice the problem with the .step file when brought back into ViaCAD, so thanks for spotting that one!

I'm not seeing any problem with the .sat file when I either open it, or import it back to ViaCAD. It just displays as ACIS_Solid497, with no mention of mesh or surfaces being present - did you perhaps import it into an existing drawing with these other things already present?

============================

So this is how these files now work for me:

1/ The .sat file loads into ViaCAD Ok, but is mangled when brought into MoI.
2/ The .step file is mangled when brought into ViaCAD, but surprisingly, comes cleanly into MoI!


The original drawing was started in MoI and transfered to ViaCAD for some other work such as filleting, so if it helps to have a description of the steps I took in each program, I think I can do that if necessary.



Martin (2).

Hi Martin,
I am only fledgling with ViaCad. I know you know it well. I just start with a default, blank ViaCad doc. The Step will have "stitching" options upon import to ViaCad. The STEp doesnt import for me in MoI.

I did find in ViaCad Some "Stitching gap parameters" that were set at .1 or something. This can be very large with this little disappearing fillets. Essentially, the re-stitching with the default ViaCad DOC and re-exporting made a good SAT from Viacad back to MoI. The mesh and surfaces object type were kindof random and not reproducable. Most of the time it reported as a solid too. But if it said "solid" and I chose "stitch", I would get a dialogue that says "all surfaces already seperated" or something like that. I'll try to do a video to see if I can show any of the anomolies.

Maybe a short description of how you originally brought the MoI model into ViaCad before the extra fillet work, and how you exported these files back out.

But this is all extraneous. Michael is looking at the underlying issues and may discover a bug to be fixed. I just jumped in as a means to help me understand the workflow with ViaCad also. If you want to continue with me, thats good for me, but now necessary. Talk later.

Hi, BurrMan.

The main thing I was trying to understand was how to use MoI to construct the section between the cylinder and the retangular block.

In ViaCAD Pro v7 I can use the Lofted Solid tool to make the transition, I couldn't see an equivalent in MoI, so I experimented with the construction.

Working in MoI, my method was to extrude four rectangular surfaces and four semi-circular surfaces (for the cylinder), which I then joined piece by piece with the Blend tool and using a Bulge of about 1.3 to get the right shape. I then capped the ends and used the Join tool to make it into a solid.

My attempts to fillet the curvy edges were a bit hit & miss - I knew this would stress MoI's filleter due to the fade-out of the edges, but the slightly odd thing was that some fillets were made underneath the geometry whilst retaining the areas that should have been deleted.

At this point I think I exported to ViaCAD as a .sat file and it came in looking Ok.

I tried to use ViaCAD to fillet and shell the part, which initially failed. The Check Object tool reported the solid as being damaged (edge gaps, I think) and also offered the option to repair it. After which this part filleted and shelled OK.

I made .sat and .step exports, with the intention of bringing them into MoI for further working and it was at this point that I found the problems with some wonky geometry.

I'm pretty sure there are other ways to make the part in MoI, but I'm still learning!

Martin.

Hi Martin,

> but the slightly odd thing was that some fillets were made underneath the geometry
> whilst retaining the areas that should have been deleted.

When this happens it means that the filleting engine got confused about how to fully process the entire fillet, especially with figuring out how to cut up the original object with the fillet edges. That can especially happen if one of the fillets did not quite fully extend far enough to form a totally closed boundary for cutting.

When there is some error like that in one of the latter stages of fillet calculation, it will try to return back the pieces that it was able to generate, in the hope that you might be able to use those pieces to complete the fillet by doing manual trimming.


The main thing that would probably make your construction for this case in MoI easier is an improved blend command that could use a longer chain of edges in one blend construction instead of only one pair at a time, that's something that's near the top of my list to work on for v3, it won't make it into this immiment beta but hopefully not long after.


- Michael

You can also prepare things to be easier to use with MoI's current single-edge-to-single-edge blend by running the Rebuild command on your curves before constructing surfaces from them, so that you've got surfaces in larger pieces instead of split up into smaller faces. With them configured like that you'll then be able to do just one blend to connect them, see the attached example.

But it's definitely a goal to improve Blend to make your original structure work for blending more easily too.

- Michael

Hey martin. Here's a quick look at what Michael means with using rebuild.



When he creates the "multi edge" blend, it will be very cool and give some better control.

Nice vid.....

Peace,
Rich_Art. ;-)

Michael.
Thanks for the explanation, the file, and the great software!

BurrMan.
An excellent video, much appreciated.

Both of you have helped me tremendously - I can do this in next-to-no-time now and it'll surely help others as well.



Martin (2).