Imported Models

Why is it, that imported models almost always break up a hole feature into 2
surfaces? Or at the very best, it will produce a single surface through the
hole itself, but if you select the edges of the hole, it will be split into
2 half circles.

Is there no way around this?

 

Because it was most likely nurbs or spline based data originally (pro/e,
sdrc,..) or the user selected that the data be exported as nurbs (iges
type 126/128)? It's not uncommon to see this import behavior.
We did have a option a few releases ago to heal the split data as
analytical so you would get a full circle... I don't think it works this
way now? Anyhow, that heal feature was the way around or a fix for the
split circles/arcs.
And, as jk mentioned, if you export and import using STEP or IGES, it
will go through another auto heal (if it's set) and try to convert them
into analytical.

...

 

Yeah, I've just got finished doing your dumb-ass solution as well But
it is a PITA to have to do...

I don't know why I haven't thought about the round trip (I call it
"looping"). I have used this method many times before. Just forgot I
guess....

 

Yep, as jk implied, the issue you see with cylindrical holes being
imported as 2 half-cylindrical surfaces is the originating system's
fault.

For instance, in ProE, all cylindrical surfaces are split in two. Thus,
when you export an iges from ProE, and then import that into SWX,
cylindrical surfaces may be split as well.

No idea why ProE (or some other cad packages) do this, but that is the
way it is.

 

Rhino does this too--NURBS. Rhino's fault in this case, not SW.


Jeff Mowry
Industrial Designhaus, LLC
http://www.industrialdesignhaus.com
(Remove "GETRIDOFTHIS" from email address)

 

It is a result of whatever made the translation to begin with. Very
common in Pro-E output.

I've imported plenty of UG parasolids where this doesn't happen,
though.

BTW....
Quick fix to turn NURBS back into planes and cylinders:
Export model as STEP203 (not STEP214), then reimport to SW. Sometimes
this converts Bisurface entities back to planes and conics.

Discovered this by accident, but it's been a lifesaver in the past.

 

It is a result of whatever made the translation to begin with. Very
common in Pro-E output.

I've importedplenty of UG parasolids where this doesn't happen,
though.

BTW....
Quick fix to turn NURBS back into planes and cylinders:
Export model as STEP203 (not STEP214), then reimport to SW. Sometimes
this converts Bisurface entities back to planes and conics.

Disocered this by accident, but it's been a lifesaver in the past.

 

It's a translation protocol option that's set because some (probably older
for the most part, Pro/E / Granite still) systems don't like surfaces that
are closed in one direction (cylinders, spheres, etc.). The split option
can be toggle for Rhino IGES exports. I think STEP allows setting the
option, too, but don't remember ever seeing it exposed to the user in any
software (if SWX exports don't split 'em, I guess an option does exist).
Doesn't have anything to do with NURBS, at any rate (and fwiw).

Does this cause problems or is it just an annoyance?

 

Jeff,

Just an annoyance actually. Although this is a model that I am creating a
mold from using vanilla SolidWorks (no add on software). Therefore there is
a lot of in-context stuff going on and having to deal with this kind of
stupid Sh-t throughout the design process can be a PITA and not very
efficient.

 

Thanks Tick. I'll keep that in mind in the future.