Converting from SolidWorks to OpenInventor / <Translation> issues

[Jared Goodner]

Since we primarily use SolidWorks to design robot parts, I use a file converter (3D Object Converter 4.20) to convert the .stl files (exported from SW) into .iv format.  However, I am having trouble aligning links using <translation>.  So I did an experiment--I used the data from a 10 inch cube built in SW to compare to a 10 x 10 x 10 unit "box" Body.  It looked close, however the "box" was a tad bit smaller upon closer inspection.

Is it a problem with my file converter?  Is there a scaling function that I'm missing within OpenRAVE?  Is anyone else having this problem?  How should I go about aligning links (besides guess and check)? 

Thanks,
Jared

[Rosen Diankov-2]

Hi Jared,

Sometimes iv files explicitly state the units that every 3D position
is in. Then when they are opened,  the viewer can convert into
whatever unit it wants (for example meters or inches). When I remove
the special Units annotation in an iv file, all scale issues
disappear. Open your iv file (it should be in text format), and check
if a Units tag is defined somewhere. Change that to METERS, or just
remove it altogether. Also, just to be on the paranoid side, check
that the coordinates of your iv file really are +-10.

rosen,


2008/7/31 Jared Goodner <[hidden email]>:

> Since we primarily use SolidWorks to design robot parts, I use a file
> converter (3D Object Converter 4.20) to convert the .stl files (exported
> from SW) into .iv format.  However, I am having trouble aligning links using
> <translation>.  So I did an experiment--I used the data from a 10 inch cube
> built in SW to compare to a 10 x 10 x 10 unit "box" Body.  It looked close,
> however the "box" was a tad bit smaller upon closer inspection.
>
> Is it a problem with my file converter?  Is there a scaling function that
> I'm missing within OpenRAVE?  Is anyone else having this problem?  How
> should I go about aligning links (besides guess and check)?
>
> Thanks,
> Jared
>
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[Rosen Diankov-2]

You can also try saving as vrml (or wrl). I've noticed that exporters
are better at saving in those formats than in iv.

rosen,

2008/7/31 Rosen Diankov <[hidden email]>:

> Hi Jared,
>
> Sometimes iv files explicitly state the units that every 3D position
> is in. Then when they are opened,  the viewer can convert into
> whatever unit it wants (for example meters or inches). When I remove
> the special Units annotation in an iv file, all scale issues
> disappear. Open your iv file (it should be in text format), and check
> if a Units tag is defined somewhere. Change that to METERS, or just
> remove it altogether. Also, just to be on the paranoid side, check
> that the coordinates of your iv file really are +-10.
>
> rosen,
>
>
> 2008/7/31 Jared Goodner <[hidden email]>:
>> Since we primarily use SolidWorks to design robot parts, I use a file
>> converter (3D Object Converter 4.20) to convert the .stl files (exported
>> from SW) into .iv format.  However, I am having trouble aligning links using
>> <translation>.  So I did an experiment--I used the data from a 10 inch cube
>> built in SW to compare to a 10 x 10 x 10 unit "box" Body.  It looked close,
>> however the "box" was a tad bit smaller upon closer inspection.
>>
>> Is it a problem with my file converter?  Is there a scaling function that
>> I'm missing within OpenRAVE?  Is anyone else having this problem?  How
>> should I go about aligning links (besides guess and check)?
>>
>> Thanks,
>> Jared
>>
>> -------------------------------------------------------------------------
>> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
>> Build the coolest Linux based applications with Moblin SDK & win great
>> prizes
>> Grand prize is a trip for two to an Open Source event anywhere in the world
>> http://moblin-contest.org/redirect.php?banner_id=100&url=/
>> _______________________________________________
>> Openrave-users mailing list
>> [hidden email]
>> https://lists.sourceforge.net/lists/listinfo/openrave-users
>>
>>
>

[Mike Vande Weghe]

Jared,

  I've also noticed that Openrave has (or at least _had_) problems with
correctly interpreting the units specified in the .iv files.  Even
though the rendering looked correct, the collision-detection was not
paying attention to the units specified, so different models could end
up having hugely different scales.  I worked around it by generating
every .iv file in meters (to do this in Pro/Engineer, I create a meter
version of my part, and then save it again as the .iv).  Mixing meters
with inches or even cm or mm leads to big problems.

I also output each .iv file with its coordinate system aligned along the
joint axis, so that I can place them exactly.  We've never had problems
with links not lining up the way we wanted.

Hope that helps,

  Mike

Jared Goodner wrote:

> Since we primarily use SolidWorks to design robot parts, I use a file
> converter (3D Object Converter 4.20) to convert the .stl files
> (exported from SW) into .iv format.  However, I am having trouble
> aligning links using <translation>.  So I did an experiment--I used
> the data from a 10 inch cube built in SW to compare to a 10 x 10 x 10
> unit "box" Body.  It looked close, however the "box" was a tad bit
> smaller upon closer inspection.
>
> Is it a problem with my file converter?  Is there a scaling function
> that I'm missing within OpenRAVE?  Is anyone else having this
> problem?  How should I go about aligning links (besides guess and
> check)?
>
> Thanks,
> Jared
> ------------------------------------------------------------------------
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> ------------------------------------------------------------------------
>
> _______________________________________________
> Openrave-users mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/openrave-users
>