XANSYS Message: 16522 [Go back to message list] [bookmark on del.icio.us]
Average Rating: 5 (1 votes) Subject: Re: IGES import with subsequent creation of a Solid model Author: Sheldon Imaoka Date: 2000-10-11 23:04:00Thanks, John, for added explanations. I must admit I'm still confused, unless SHAPES was added in 5.0 for Booleans and SHAPES MT at 5.4-ish for importing. Ahh, whatever. Without meaning to rub anyone the wrong way, I know that many try to avoid this stuff like the plague, anyway.
Bathrobe, nightgown, bunny slippers... I won't ask, and -- no offense intended -- I *don't* want to know. :)
Laters, Sheldon CSI
----- Original Message ----- To: Sent: Wednesday, October 11, 2000 6:38 PM
> For more info on XOX you can go to their web site www.xox.com and check out > their stuff. They list ANSYS Inc. as a customer in their "Partners" > section.
> I seem to remember that XOX entered the ANSYS universe when 5.0 hit the > streets in 1991 or 1992. ANSYS wanted a smarter modeler than the one they > had in 4.X and instead of starting over they obtained the XOX engine and > integrated it's boolean functionality within ANSYS. The big problem is that > native ANSYS geometry is in one form (b-spline, nurb, whatever...) and XOX > wants something else, so every time ANSYS performs a boolean it has to > translate native ANSYS geometry into XOXese (for lack of a better term), > have XOX import it and do the boolean, then export the booleaned entities > and translate them back into ANSYSese. It doesn't take a rocket scientist > (although I'm sure several are reading this) to see that there are 3 places > for failure to occur in this process; the first translation, the boolean > operation itself, and the second translation. After you consider all that > goes on beneath the sheets, it's not suprising that we see "Change BTOL and > try again" as often as we do. I sometimes find it hard to believe that > we've been having this kind of fun for 8 or9 years now.
> I'm sure that others can add to this discussion, but this is my > understanding of things.
> As an aside to this, it appears as though the native ANSYS geometry needs to > be REALLY precise, which explains the problem in doing boolean operations > (the operation is only as precise as the engine that performs it) as well as > ANSYS' difficulty in importing sloppy geometry files from such fine programs > as CATIA. People tell me that geometry from Pro/E usually imports pretty > well, and that may be because their geometry engine is fairly new and is > "tighter" than the geometry engine in older programs like CATIA V4. I am > curious how easily CATIA V5 geometry is imported into ANSYS. Has anyone > done this yet?
> Before anyone mentions it, yes I am reponding from home, and yes this means > that I am sick and demented. I can't offer any explanation other than it's > the only way I know how to be.
> I refuse to comment on whether I am wearing bunny slippers as I type this.
> John Crawford > crawford@a...
> ----- Original Message ----- > From: Mitch Voehl > To: > Sent: Wednesday, October 11, 2000 7:51 PM > Subject: Re: [xansys] IGES import with subsequent creation of a Solid model
> > 'MicroTopololgy'. Yes, that's the word I was looking for. Thank you > > for refreshing my memory regarding the faceted surface representations.
> > You state your belief that:
> > > Shapes has its own Boolean > > > operations, and so does ANSYS standard modeler. Hence, if a user > > imports a > > > model that uses Shapes modeler, it remains in the Shapes modeler. > > Likewise, > > > if a user imports a model that is in the ANSYS standard modeler, it > > never > > > uses Shapes (XOX), but it only uses ANSYS standard modeler operations.
> > Hmmm, if the ANSYS standard modeler has its own set of Boolean > > operations, what purpose has the XOX modeler served over all of these > > past years? It is my impression that ANSYS started using XOX many years > > ago, perhaps in the late 4.x revs or at least in the early 5.x revs. > > (XOX was a Minneapolis company, so I kinda paid attention to it for > > awhile.) Surely the XOX Shapes modeler was essential for something, > > prior to its being used for the "Allow defeaturing" form of geometry > > import introduced at approximately rev 5.4?
> > OK, have I beaten this topic to death yet? :-)
> > Anyway it seems as though there is uncertainty within the user community > > regarding how ANSYS handles solid geometry. (Or at least, Mark, you, > > and I had somewhat different impressions as to how things worked.) > > Would anyone at ANSYS, Inc. care to clarify the situation?