[cgma-dev] Inconsistency in getEntities for iGeom interface. Causes problems in iRel.
Paul Wilson
wilsonp at engr.wisc.edu
Mon Jun 23 15:06:07 CDT 2014
Hi everyone,
Patrick and I have discussed this and have come up with the following
proposal for a revision of how iGeom_CGMA handles RefVolumes and Body's.
1. All references to iBase_REGION will refer only to entities of type
RefVolume in CGM.
2. All entities that are returned by iGeom will be RefEntities and not
CubitEntities
3. At the time of loading file, based on an option based to
iGeom_load(), all entities of type Body in CGM that contain more
than a single volume, will be converted to RefGroup's and tagged to
distinguish them from the original RefGroup's
The last of these may be subject to the most conversation, but it seemed
like a useful approach to use because it:
* had little to no effect on the API of iGeom
* preserves access to CGM/ACIS bodies
* is the least intrusive in the implementation of iGeom_CGMA
If a user does NOT pass in the option (e.g. "CONVERT_BODY_TO_GROUP"),
then no bodies will be accessible through iGeom. If a user does pass in
this option, any call to iGeom_getEntSets will return both the original
RefGroups and the additional RefGroups that were generated automatically
from Bodies. It will be up to the user to filter between them using the
available tag.
Finally, since every RefVolume in ACIS always has a Body in which it is
a member, it seems best to only convert Bodies that contain >1 RefVolume
to avoid creating far more RefGroups than necessary.
We'd like to embark on these changes soon, but welcome any comments or
feedback. I'm sure we've missed something!
Paul
On 06/17/2014 09:00 AM, Jane Hu wrote:
> So, I will add RefVolume to the return list
> of iGeom_get_adjacent_entities() as the result of the discussion.
>
> CubitEntity only has derived classes of RefEntity
> and CubitCoordinateSystem, iGeom_CGMA.cc only uses RefEntity as
> instance of the object.
>
> Jane
>
>
> On Mon, Jun 16, 2014 at 11:35 AM, Jane Hu <janejhu at gmail.com
> <mailto:janejhu at gmail.com>> wrote:
>
> See comments below...
>
>
> On Mon, Jun 16, 2014 at 10:22 AM, Paul Wilson
> <wilsonp at engr.wisc.edu <mailto:wilsonp at engr.wisc.edu>> wrote:
>
> Hi Jane,
>
> I think this needs a thorough review! Patrick and I hunted
> through iGeom_CGMA and found some inconsistencies in a few places.
>
> First, there is an inconsistency between returning pointers to
> RefEntity and pointers to CubitEntity. This is probably less
> important, but should probably be resolved in any change.
>
> I see RefEntity is inherited from CubitEntity, and CubitEntity is
> a pure virtual class. So even you got pointers to CubitEntity, you
> have to instantiate it to RefEntity objects.
>
>
> Second, there are places where the geometry is queried for
> entities of dimension=3 (returning RefVolumes) and places
> where the geometry is queried for entities of
> type=iGeom_REGION (== Body).
>
>
> In this case, I can return both bodies and refvolumes, so after
> user gets the refentity list back, he can cast to see if they are
> bodies or refvolumes, and choose to keep what ever he needs.
>
>
> This means that 2 calls into the interface that should resolve
> to the same entity may not do so for both reasons.
>
> All of this is related to the fundamental difference between
> the iGeom types (equivalent to vertex, edge, face, volume) and
> the CGM/ACIS types (equiavlent to vertex, edge, face, volume,
> body). I think Tim's suggestion is the best, but will require
> some substantial effort.
>
> Paul
>
>
> On 06/16/2014 10:14 AM, Jane Hu wrote:
>> I see in iGeom_CGMA.cc file,
>> function iGeom_get_adjacent_entities, if asks for 3-D
>> refentities, it returns body list. In CGM, bodies are not
>> necessary to be 3-D entities, it may contain single surface
>> or shell. Should we change the return to be only refvolumes
>> which are 3-D entities (I prefer this, makes more sense)? Or
>> I can return both bodies and refvolumes in the returned
>> refentity list. Depending on your user case, I can return one
>> of the two choices.
>>
>> Jane
>>
>>
>> On Mon, Jun 16, 2014 at 9:32 AM, Jane Hu <janejhu at gmail.com
>> <mailto:janejhu at gmail.com>> wrote:
>>
>> Yes, it returns a list of refVolume's which are RefEntities.
>>
>> Jane
>>
>>
>> On Sun, Jun 15, 2014 at 11:55 PM, Patrick Shriwise
>> <shriwise at wisc.edu <mailto:shriwise at wisc.edu>> wrote:
>>
>> Hi Jane,
>>
>> Will the ref_volumes() method return RefEntities?
>>
>> Patrick
>>
>> On Jun 15, 2014, at 3:56 PM, Jane Hu
>> <janejhu at gmail.com <mailto:janejhu at gmail.com>> wrote:
>>
>>> Look at line 6454, if you have body's pointer,
>>> directly call ref_volumes() will work. It's not an
>>> iGeom interface function, but you can access it in
>>> iGeom.
>>>
>>> Good luck!
>>>
>>> Jane
>>>
>>>
>>> On Sat, Jun 14, 2014 at 8:55 AM, Patrick Shriwise
>>> <shriwise at wisc.edu <mailto:shriwise at wisc.edu>> wrote:
>>>
>>> Hi Jane,
>>>
>>> I looked around for this but didn't see it, is
>>> there a specific line/function you were thinking
>>> of? Good to know the ref_volume information is
>>> so easy to get to, but it doesn't seem that its
>>> part of the iGeom interface. The issue being
>>> that there's no way to access a body's volumes
>>> via iGeom.
>>>
>>> Cheers,
>>>
>>> Patrick
>>> On 06/13/2014 11:26 PM, Jane Hu wrote:
>>>>
>>>>
>>>>
>>>>
>>>> Is there a way to get volumes within
>>>> bodies via iGeom?
>>>>
>>>>
>>>> See example in iGeom_CGMA.cc,
>>>> body->ref_volumes(volumes).
>>>>
>>>> Jane
>>>>
>>>>
>>>> --
>>>> Patrick C. Shriwise
>>>> Research Assistant
>>>> University of Wisconsin - Madison
>>>> Engineering Research Building - Rm. 428
>>>> 1500 Engineering Drive
>>>> Madison, WI 53706
>>>> (608) 446-8173 <tel:%28608%29%20446-8173>
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Jane Hu
>>>>
>>>> Asst. Researcher
>>>> Dept. of Engineering Physics
>>>> UW @ Madison
>>>>
>>>> "And we know that for those who love God, that
>>>> is, for those who are called according to his
>>>> purpose, all things are working together for
>>>> good." (Romans 8:28)
>>>
>>>
>>>
>>>
>>> --
>>> Jane Hu
>>>
>>> Asst. Researcher
>>> Dept. of Engineering Physics
>>> UW @ Madison
>>>
>>> "And we know that for those who love God, that is,
>>> for those who are called according to his purpose,
>>> all things are working together for good." (Romans
>>> 8:28)
>>
>>
>>
>>
>> --
>> Jane Hu
>>
>> Asst. Researcher
>> Dept. of Engineering Physics
>> UW @ Madison
>>
>> "And we know that for those who love God, that is, for
>> those who are called according to his purpose, all things
>> are working together for good." (Romans 8:28)
>>
>>
>>
>>
>> --
>> Jane Hu
>>
>> Asst. Researcher
>> Dept. of Engineering Physics
>> UW @ Madison
>>
>> "And we know that for those who love God, that is, for those
>> who are called according to his purpose, all things are
>> working together for good." (Romans 8:28)
>
> --
> -- ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ --
> Paul Wilson ~ UW-Madison ~608-263-0807 <tel:608-263-0807> ~ cal:http://bit.ly/pphw-cal
> Professor, Engineering Physics. ~http://cnerg.engr.wisc.edu
> Faculty Director, Advanced Computing Infrastructure
>
>
>
>
> --
> Jane Hu
>
> Asst. Researcher
> Dept. of Engineering Physics
> UW @ Madison
>
> "And we know that for those who love God, that is, for those who
> are called according to his purpose, all things are working
> together for good." (Romans 8:28)
>
>
>
>
> --
> Jane Hu
>
> Asst. Researcher
> Dept. of Engineering Physics
> UW @ Madison
>
> "And we know that for those who love God, that is, for those who are
> called according to his purpose, all things are working together for
> good." (Romans 8:28)
--
-- ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ --
Paul Wilson ~ UW-Madison ~ 608-263-0807 ~ cal: http://bit.ly/pphw-cal
Professor, Engineering Physics. ~ http://cnerg.engr.wisc.edu
Faculty Director, Advanced Computing Infrastructure
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