2004-august.txt

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From alames at sandia.gov  Wed Aug  4 16:58:55 2004
From: alames at sandia.gov (Ames, Arlo)
Date: Wed Aug  4 17:00:14 2004
Subject: [Acis-alliance] Merge similar face in a Body ?
Message-ID: <[e-mail]>

1.  I would first check to see whether there's a way to prevent the
duplicate from being created in the first place.  Your algorithms have some
kind of degeneracy that worries me.

2.  You might try api_regularise to see if it clears up the degeneracy, but
it's a big hammer with possibly the wrong semantics.

3.  Failing those, I would write code that essentially duplicates the
api_check functionality to determine the duplicate information (maybe just
call api_check and traverse the returned failures?).  I seem to recall there
being an api_delete_face function that removes a single face from the model,
or you can do this by direct interface calls.  Note that you'll be deleting
2 faces and stitching closed a resulting gap, so whatever you do has to
close the gap.  Note that api_cover_... is a WRONG thing to do, as it will
try to create a zero-area face, and will have trouble figuring out the shape
of the surface to cover the hole with.

Arlo Ames
[e-mail]


-----Original Message-----
From: Samul Mazel [mailto:[e-mail]] 
Sent: Wednesday, August 04, 2004 8:45 AM
To: [e-mail]
Subject: [Acis-alliance] Merge similar face in a Body ?


Hello,

I have a little problem, in a body i have two faces with same vertex and
edges, I want to make an operation to obtain only one, and I want to keep
one. With a check I have this :

acis> (entity:set-color (part:load "D:/Mazel_Samuel/Project1/res.sat" )
GREEN)
()
acis> (entity:check (entity 1))

entid  73082120: Error: duplicate vertex
 at 5.000000000000 -2.000000000000 -2.000000000000
        other vertex is 73763912
entid  73081784: Error: duplicate vertex
 at 5.000000000000 2.000000000000 -2.000000000000
        other vertex is 73765208
entid  73081448: Error: duplicate vertex
 at 5.000000000000 -2.000000000000 2.000000000000
        other vertex is 73763528
entid  73766936: Error: duplicate vertex
 at 5.000000000000 2.000000000000 2.000000000000
        other vertex is 73766792
entid  73079816: Error: duplicate vertex
 at -5.000000000000 2.000000000000 -2.000000000000
        other vertex is 73764632
entid  73080824: Error: duplicate vertex
 at -5.000000000000 -2.000000000000 -2.000000000000
        other vertex is 73765736
entid  73764776: Error: duplicate vertex
 at -5.000000000000 2.000000000000 2.000000000000
        other vertex is 73763480
entid  73765592: Error: duplicate vertex
 at -5.000000000000 -2.000000000000 2.000000000000
        other vertex is 73764296

checked:
        3 lumps
        3 shells
        0 wires
        20 faces
        22 loops
        88 coedges
        44 edges
        32 vertices
(#[entity 2 25] #[entity 3 25] #[entity 4 25] #[entity 5 25] #[entity 6 25]
#[entity 7 25]  #[entity 8 25] #[entity 9 25]) I want 18 Faces 20 loops 36
edges and 26 vertices What you suggest ? thanks Samuel

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From alames at sandia.gov  Wed Aug  4 17:08:33 2004
From: alames at sandia.gov (Ames, Arlo)
Date: Wed Aug  4 17:09:06 2004
Subject: [Acis-alliance] Stitching faces of seperate entities
Message-ID: <[e-mail]>

I don't know what mesher you're using, but I know the CUBIT mesher is
capable of recognizing coincident faces and taking care of the mechanics
itself.  I'd first look at the documentation for the meshing algorithm, as
any mesher capable of meshing assemblies has to be able to perform this bit
of work.

Api_stitch is definitely the wrong tool, as it's looking to stitch together
faces that have unmatched COEDGEs on their boundaries.  Since you created
all your boundaries using solid operations, there are no unmatched
boundaries.  

Further, you'd need to flag the coincident faces as two-sided, and use
cellular topology to model them correctly in ACIS.  I'm not sure any current
meshing algorithm correctly uses the ACIS cellular topology representation,
so I really wouldn't start there without first being very certain that your
mesher is cellular-aware.  Otherwise you're barking up a somewhat costly
tree.

Again, dollars to doughnuts that your mesher does what you need, and that
your model is adequate.  You just need to tell it that you want it to find
coincident faces.

Arlo Ames
[e-mail] 

-----Original Message-----
From: Martin Sherburn [mailto:[e-mail]] 
Sent: Wednesday, August 04, 2004 10:40 AM
To: [e-mail]
Subject: [Acis-alliance] Stitching faces of seperate entities


Hello,

I'll start off by explaining what it is that i'm trying to do:

I start out with a solid block entity, then a create a number of thin
cylindrical shaped volumes that go through the block. I then subtract the
cylinders from the block, leaving a block full of holes. But I still keep a
copy of the cylinders, and intersect them with the original block so that
the cylinders do not extend out past the boundaries of the block.

So essentially what i end up with is the same as what i started with, a
block. But the block is seperated into several volumes: The block with the
holes in it, and the trimmed cylinders. Now what i would like to do is to be
able to stitch the internal faces of the block with the external faces of
the cylinders. So that I only have one face between the boundaries of the
cylinders and the block.

What function should i use to do this? I have tried using api_stitch,
passing in the list of entities i have. but it doesn't seem to do the job!

The reason I want to do this is because I will use the model to mesh it
using another peice of software, and use the mesh to perform finite element
simulations. And in order to get a valid mesh from this other software, i
need the faces to be the same or the nodes at the boundaries will not
coincide.

Any help would be greatly appreciated,

Thank you,

Martin.


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From akcrawford at gscad.com  Wed Aug  4 13:03:32 2004
From: akcrawford at gscad.com (Crawford, Alan)
Date: Fri Aug  6 13:34:58 2004
Subject: [Acis-alliance] Stitching faces of seperate entities
Message-ID: <[e-mail]>

If I understand exactly what you are trying to do, the answer is simple:

1.  Convert the cylinders to double sided (api_body_to_2d)
2.  Subtract the cylinders from the block with NONREG_SUBTRACTION.

Nonregularised subtraction can be unreliable if multiple subtractions create
overlapping/coincident faces, especially if the objects are composed of
spline surfaces.  However, this does not sound like a problem in your case.

-----Original Message-----
From: Martin Sherburn [mailto:[e-mail]]
Sent: Wednesday, August 04, 2004 12:40 PM
To: [e-mail]
Subject: [Acis-alliance] Stitching faces of seperate entities


Hello,

I'll start off by explaining what it is that i'm trying to do:

I start out with a solid block entity, then a create a number of thin
cylindrical shaped volumes that go through the block.
I then subtract the cylinders from the block, leaving a block full of holes.
But I still keep a copy of the cylinders, and intersect them with the
original block so that the cylinders do not extend out past the boundaries
of the block.

So essentially what i end up with is the same as what i started with, a
block. But the block is seperated into several volumes: The block with the
holes in it, and the trimmed cylinders. Now what i would like to do is to be
able to stitch the internal faces of the block with the external faces of
the cylinders. So that I only have one face between the boundaries of the
cylinders and the block.

What function should i use to do this? I have tried using api_stitch,
passing in the list of entities i have. but it doesn't seem to do the job!

The reason I want to do this is because I will use the model to mesh it
using another peice of software, and use the mesh to perform finite element
simulations. And in order to get a valid mesh from this other software, i
need the faces to be the same or the nodes at the boundaries will not
coincide.

Any help would be greatly appreciated,

Thank you,

Martin.


This message has been scanned but we cannot guarantee that it and any
attachments are free from viruses or other damaging content: you are
advised to perform your own checks.  Email communications with the
University of Nottingham may be monitored as permitted by UK legislation.


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From Nilesh.Joshi at asu.edu  Fri Aug  6 17:14:30 2004
From: Nilesh.Joshi at asu.edu (Nilesh Joshi)
Date: Fri Aug  6 17:17:24 2004
Subject: [Acis-alliance] ACIS 7.0 STEP -> SAT
In-Reply-To: <[e-mail]>
Message-ID: <[e-mail]>

Hi,
I am using ACIS 7.0 and am converting a STEP AP 203 file into entity_list.
After doing some processing, I output a STEP AP 203 file back.
both the functions are performed using acis APIs.
but, after this, i need to map the advanced_face entities in the output STEP
AP 203 file to the FACE entities in ACIS...one to one.
does anyone have any idea if there is any clue acis gives so I can map the
faces in AP 203 file to those in acis...
some attribute may be...
please let me know if someone knows something.
If you have done this with new version of ACIS, please let me know too.
Thanks a lot.

With Regards
-Nilesh Joshi
Design Automation Laboratory
Arizona State University 
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From Nilesh.Joshi at asu.edu  Fri Aug  6 17:35:07 2004
From: Nilesh.Joshi at asu.edu (Nilesh Joshi)
Date: Fri Aug  6 17:38:19 2004
Subject: [Acis-alliance] autotest_struct
In-Reply-To: <[e-mail]>
Message-ID: <[e-mail]>

Hi,
can anyone please give me some information about autotest_struct.
it is used in one of the APIs I use, and it stores some important
information.
But, this class is not even mentioned in the documentation.
If anyone has used it, please let me know.
Thanks.

With Regards
-Nilesh Joshi
Design Automation Laboratory
Arizona State University 
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From c.noelte at web.de  Mon Aug  9 02:13:10 2004
From: c.noelte at web.de (=?iso-8859-1?Q?Cornelia_N=F6lte?=)
Date: Mon Aug  9 02:13:47 2004
Subject: [Acis-alliance] Help rotate selected object
Message-ID: <[e-mail]>

Hi,
I am using Acis R13 and Hoops 10. I like to perform a rotation for selected
primitives. The translation works fine but the rotation in the file
HSOpObjectRotate isn't implemented for Acis. I tried to write the rotation
on my own but I can't get two identic results for the rotation for Hoops and
for Acis although I used the same angle and vector.

Can anyone help and tell me what I do wrong or how to do it?
Thanks
Cornelia Noelte

Some code fragments:

		Hpoint rotate_object;
		SPAvector rot_obj;
		SPAtrans rotation_transf;
...

		HC_Rotate_Object_Offaxis (rotate_object->x,
rotate_object->y, rotate_object->z, theta);
		

		rot_obj.set_x(rotate_object->x);
		rot_obj.set_y(rotate_object->y);
		rot_obj.set_z(rotate_object->z);


		rotation_transf = rotate_transf(theta,rot_obj);
		o = api_transform_entity(body, rotation_transf);




From juergen.wehr at stz-wuerzburg.de  Tue Aug 10 03:32:00 2004
From: juergen.wehr at stz-wuerzburg.de ([e-mail])
Date: Mon Aug  9 08:04:31 2004
Subject: [Acis-alliance] ACIS Training
Message-ID: <[e-mail]>

Hello everybody,

I'm searching for peaple, who used ACIS Trainings in Germany.

Does anybody know firms, which offer ACIS Training? (Spatial, ...?)

Can somebody give an evolution of Trainings? 

Juergen Wehr



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From zhangkm at hhuc.edu.cn  Tue Aug 17 02:30:11 2004
From: zhangkm at hhuc.edu.cn (张坤明)
Date: Tue Aug 17 02:39:38 2004
Subject: [Acis-alliance] how to project a "body" onto a "plane" and get a
	"face"
Message-ID: <[e-mail]>