[cgma-dev] Inconsistency in getEntities for iGeom interface. Causes problems in iRel.
Patrick Shriwise
shriwise at wisc.edu
Fri Jul 11 18:21:52 CDT 2014
Hi all,
I'm currently working on the changes to iGeom that Paul previously
proposed. I've hit one test when built with OCC (copy_attrib) that
suggests that tags are expected to be copied along with an entity when
using iGeom functions like copyEnt or subtractEnt. Is this the case? Are
these specifc tags that are supposed to be copied if they exist on the
original entity?
Also to be clear this has become an issue because for volume entities we
now use the RefVolume to get the volume Body and make a copy of that
body using the GeometryModifyTool. The Body we make a copy of does not
have the tags associated with the RefVolume. As a result the new Body
and the corresponding RefVolumethat we return from the function does not
have the original tags.
These tags can be transferred to the new entity before leaving the
function of course, but we're looking for the proper way to handle this
situation. Mainly it would be good to know if there is a particular tag
or tags that should be copied over to new entity upon it's creation.
Cheers,
Patrick
On 06/23/2014 03:06 PM, Paul Wilson wrote:
> 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
--
Patrick C. Shriwise
Research Assistant
University of Wisconsin - Madison
Engineering Research Building - Rm. 428
1500 Engineering Drive
Madison, WI 53706
(608) 446-8173
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/cgma-dev/attachments/20140711/83fbeab5/attachment-0001.html>
More information about the cgma-dev
mailing list