3D Interoperability

[xpz]

When we export a CUBE to a IGES file, as the following code:

---------------------------------------------------------------

 BODY *block1=NULL;
 api_solid_block( SPAposition(0,0,0), SPAposition(50,50,50),block1 );

 ENTITY_LIST ipAcisEntities;
 ipAcisEntities.add( block1 );
 SPAIAcisDocument src( &ipAcisEntities );
 SPAIDocument dst( "model.igs" );
 SPAIConverter converter;
 converter.Convert(src, dst);

---------------------------------------------------------------

We find there are 6 faces in the IGES file, not CUBE information.

How to setup the SPAIDocument to let solid infomation can be exported to IGES file?

Thanks in advance.

[bikash_parida]

Hi,

By default IGES writer writes solid as faces. If you are interested in writing solid as solid, make sure to switch on "TranslateSolidBodies" option.

Thanks

Bikash

[xpz]

it works now, thank you very much.

I have 2 more questions:

1. whether the interop has independent documentation, which list all class and functions.  Current documentation include ACIS Modeler and interop, compared to the old R17 ACIS Modeler documentation,  it is very hard to find a class and function by an index.

2. we met a problem when export STEP files. For some software, for example, CADFaster|Quickstep, it can detect all solids in the file. But for some softwares which use OpenCascde library, they can only recognize the first solid in the file. Does the STEP file has any format or version options?

Thanks in advance.

[bikash_parida]

Hi,

1) Which class and function documentation are you talking about?

2) I did not understand first part of your question, how it is linked with version of STEP file? Can you explain?

Thanks

[xpz]

1) For the current documentation, we can only start from a searching page. If we do not have too much acknowledge about ACIS or interop, it is very hard to start finding useful infomation. For example, for interop option "TranslateSolidBodies", how can we search, "Interop-articles", "interop-connect lib", or "interop IGES lib"?  So many options, which one is correct? For a new user, it is very hard to guess.

meanwhile, the search result is not very directly. For interop option "TranslateSolidBodies", through "interop-connect lib", there is one searching result, but only goes to a page without any explaination; through "Interop-articles", there are 6 searching results, we need to browse the searching-result page by page to find what we need.

But for the old ACIS help system, for example, R17 documentation, it starts with a navigation page, if I want to find some functions or class member, we can directly goto "ACIS C++ API index" page to search the function, much friendly for user.

So, our question is, whether there is any documentation for R19 or R20 use the old R17 style?

2) We are using a software "netgen" to create some special mesh for our application, this software use the OpenCascade lib to support STEP file. We found the "netgen" can only recognize the first solid in the STEP which is exported by Interop. But "netgen" can recognize the multiple solids in the STEP file which is in the "netgen" example.

Because we are new to the CAD format conversion, we don't know too much about the STEP format compatibiltiy, we are wondering whether the STEP file has version number to make it different in various software.

Thanks.

[bikash_parida]

Hi,

On 1) we will get back to you.

on 2) Yes step has version numbers. For details see

http://www.steptools.com/support/stdev_docs

Thanks

Bikash

[ejp]

xpz,

can you send me the step file you are having a problem with.  i have been working with step for many years and i can tell you if the structure in the step file is correct for representing multiple bodies...

[xpz]

The attached "2_box_stp" has two boxes, it is created by interop, 'netgen' can show only one box. But 'netgen' can show all solids in the "a203_stp".

Thank you very much.

[ejp]

although the structure used in the 2_box step is not illegal it is not the standard way multiple solid bodies are represented.  the 2_box step file actually has 2 different products which correlate to parts and each product contains a single brep.  to put 2 solid bodies into one part, one product must be defined and a relationship between the shape representations must be used.  this is the structure used in the ap203 step file and this is the structure most, if not all, cad systems would expect.  so i guess the short answer is, the interop generated step file is not incorrect but it is non-standard...

by the way, you might want to try the option EnableMultiLumpBody to see if that makes a difference...

[rbagley]

---

xpz wrote:

1. whether the interop has independent documentation, which list all class and functions.  Current documentation include ACIS Modeler and interop, compared to the old R17 ACIS Modeler documentation,  it is very hard to find a class and function by an index.

xpz:

Did you try browsing in the InterOp Library Reference?  In answer to your later question: no, the online version is the only available documentation.  We completely converted from the old system to the current one in R19.

Best,

Ray Bagley