CIS/2 - SteelVis scale

[Martin Sherburn]

I am using SteelVis to convert CIS/2 files into VRML. I have noticed
that the scale of the models can vary a lot between models. If you put
two different models side-by-side, sometimes one of the models will
appear like a miniature version compared to the other. I assume this
is because some models are described in meters, others in feet and
inches, other in millimeters, etc...

Ideally I'd like all dimensions to be in millimeters, is there any
robust way for me to tell what the units are so that I can scale
accordingly? Either in the VRML file, an option in SteelVis? The only
thing I could find relating to units in SteelVis is "Report Dimensions
in: Feet inches or Native units". But as far as I can tell this does
not affect the actual coordinates in the VRML file?

[Robert Lipman]

Martin,

You are correct that CIS/2 models can be in millimeters, meters,
inches, or feet.

SteelVis does not do any conversion of the units, except for
millimeters which are converted to meters for the VRML model.
SteelVis gives a warning message when this happens. Millimeters are
converted to meters for the VRML model to make the navigation of the
VRML model easier and for other issues like the near and far clipping
planes.

At the end of the output from SteelVis in the status window, there is
a line of information that starts with "Translation options". The
last piece of information is the units from the CIS/2 file. This
information is also in the VRML file at the very end. Of course if it
says millimeters, then the VRML model is in meters.

The option you found "Report Dimensions in: Feet inches or Native
units" only has to do with the summary report and text popups.

There is no user option to convert the units.

It is possible to hand edit the VRML file and put a Transform node,
with an appropriate scale, around everything.

---
Bob Lipman
http://cic.nist.gov/lipman/

[Martin Sherburn]

Thanks Bob,

You are a great help as usual. I think I have everything scaled to
millimeters now regardless of what the native units are.

I have searched through all the sample CIS/2 files I have (mostly ones
from your website, http://cic.nist.gov/vrml/cis/Sample_CIS2_Files.zip).
I found the following possiblities:

Inch, Foot, Feet and Millimeter.

I could not find any models with units of "Meter", would that be the
correct string to use? Are there are any other units that might be
found in a CIS/2 file that I have not covered?

Thanks,

Martin.

[Robert Lipman]

Martin,

There are no other units than Inch, Foot, Feet and Millimeter that I
can think of. However, the spelling uses the British spelling with
the 'e' and 'r' reversed so it millimetre and metre. There might not
be any CIS/2 files the use metres as the units.

Another issue is that it is possible for CIS/2 files to have mixed
units, i.e. feet and inches or even inches and millimeters. I've seen
it mostly in CIS/2 files from RISA.

Bob

On Sep 30, 4:32 am, Martin Sherburn <m.sherb...@acecad.co.uk> wrote:
> Thanks Bob,
>
> You are a great help as usual. I think I have everything scaled to
> millimeters now regardless of what the native units are.
>
> I have searched through all the sample CIS/2 files I have (mostly ones

> from your website,http://cic.nist.gov/vrml/cis/Sample_CIS2_Files.zip).