where does geometry exist

[multicaduser]

Basic parasolid question. When geometry is wave-linked, does a copy of the actual geometry reside in that file or just a pointer? My understanding is that there is a copy of the actual geometry and that there is a pointer to where it comes from. I know that is over simplistic but it would be appreciated if someone could elaborate. This is more or less an academic discussion we are having, but there are some real implications involved too.

 

[JohnRBaker]

"My understanding is that there is a copy of the actual geometry and that there is a pointer to where it comes from."

You're basically correct. The geometry, or more accurately, the topology of the bodies are copied into the work part and a record of where it came from is created.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[multicaduser]

Thanks John. I know this follow up question may be out of your field, but is this true for all major cad packages that use the parasolid kernel?

 

[JohnRBaker]

While it is basically true that virtually all 'major' CAD vendors have licensed Parasolid from Siemens in one form or another, not all of them are using it as their modeling kernel. For example, Dassault Systems has licensed Parasolid but it's not used as part of Catia, but is the kernel in SolidWorks. Of course Solid Edge is based on Parasolid.

For a list of our CAD and AEC licensees of Parasolid (at least those who allow us to publicize their names), please go to:

http://www.plm.automation.siemens.com/en_us/products/open/parasolid/customers/cad-aec.shtml

But lets not forget that Parasolid is used in many more products than pure CAD applications, that are also the so-called CAM vendors:

http://www.plm.automation.siemens.c...n/parasolid/customers/cam-manufacturing.shtml

And CAE:

http://www.plm.automation.siemens.com/en_us/products/open/parasolid/customers/cae-analysis.shtml

And then there are those people developing products to help exchange data between systems:

http://www.plm.automation.siemens.com/en_us/products/open/parasolid/customers/data-exchange.shtml

And then there those organizations who have licensed Parasolid for there own internal use and who may not be developing any commercial applications:

http://www.plm.automation.siemens.c...rasolid/customers/enterprise-government.shtml

As well as universities and pure research organizations:

http://www.plm.automation.siemens.c...n/parasolid/customers/academic-research.shtml

But now that you've brought the topic up, we also supply other 'components' used to create CAD and other design and manufacturing systems including things like D-Cubed for 2D and 3D constraint engines (in some respects, D-Cubed is used even more widely across the CAD spectrum than is Parasolid and by a lot more of our direct competitors):

http://www.plm.automation.siemens.com/en_us/products/open/d-cubed/customers/index.shtml

In general, Siemens PLM Software is providing a lot of the technology being used out there today as can be seen by what we call our 'Components' business:

http://www.plm.automation.siemens.com/en_us/products/open/index.shtml

I know that this is bunch of links to an ostensibly a 'Marketing' site, but you did ask a question which could only be answered in that manner.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[multicaduser]

Wow....that's a lot of good information. However, my actual question is, do all these system perform the same as NX in that they copy the topology of the bodies when they perform wave link or similar function?

 

[Toost]

I don't think we know that. It's can be a secret of the respective software developer. ( Everybody tries to hide some stuff just to make the competitors THINK that they have invented something unique. Or place patents on things to make it more difficult for the competition. :- )

Regards,
Tomas

 

[multicaduser]

Thanks for the information. We're in the process of evaluating switching from NX to another cad system which is more widely used in our company. While I consider NX far more capable than most systems, it does tend to create issues when trying to work in an environment with dissimilar systems. When claims are made that just don't sound true to the ear it's best to investigate. Informed decisions have fewer issues.

 

[cowski]

It is my understanding that the parasolid kernel creates/manages the model topology. Then there is the NX layer that presents an interface to the user and translates those commands to the parasolid kernel. So, for example, when you use the extrude dialog box, what you see doesn't necessarily line up with parasolid terminology/commands; the NX layer presents options and translates the user input into commands that parasolid understands. Parasolid creates the geometry and NX manages and displays the result. My guess would be that the NX layer manages the "links" of the wave links and places the geometry from parasolid into the correct file; I doubt that the parasolid kernel is managing the links. This means that other packages could manage such links differently, they would be handled by the proprietary code layer between the user and parasolid kernel.

But, that's just my semi-educated guess. I could be completely wrong.

www.nxjournaling.com

 

[JohnRBaker]

Yes, cowski that's basically correct but the thing to remember that a if you export a Parasolid model out of any application that uses the Parasolid kernel, that model should be able to be imported into any other system using Parasolid with no loss os accuracy or fidelity. Now it will only be a topological model, that is no features or design intent, but it will dimensionally accurate and a valid solid/surface model.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.