Re: [CAD_CAM_EDM_DRO] digitizers a different approach

Hi,

Perhaps the conversion could be done by a two stage process. Say you want to
get the profile of a 'hump', project the grid from above (down the 'Z' axis)
and photograph from the side ('X' or 'Y' axis). then take this photo into
Corel Draw, use the 'Trace' command to leave just the grid lines showing the
contours and export the file into a CAD program. Then you can use a
'Distance' or measure command to get individual heights and then correct
them by proportioning them to a physical measurement of, say, overall
height. Do the same for both 'X' and 'Y' axes and you should be able to get
a true map of each point of the grid. The difficulty with this method, apart
from the length of time it is likely to take to work out all the heights, is
that hollows in the surface may not be visible from the side and so will not
be seen on the photographs.

Ian
--
Ian W. Wright
Sheffield UK
www.iw63.freeserve.co.uk

----- Original Message -----
From: "Jon Elson" <jmelson@...>
To: <CAD_CAM_EDM_DRO@egroups.com>
Sent: 07 January 2001 06:44
Subject: Re: [CAD_CAM_EDM_DRO] digitizers a different approach


>
>
> terrylr@... wrote:
>
> > she works for and they have a home-grown 3d
> > scanner. basically, from what she described
> > they project a precise grid pattern on the object.
> > depending on the object they have developed different
> > grid patterns, the normal grid they use is 400x400.
> > (quick math would give a point cloud of 160,000 data
> > points.) using a digital camera they take two
> > pictures of the object with the grid pattern projected
>
> Wow! This is what a few of the expensive machines do.
> I haven't seen any affordable software to do the conversion.
> Any chance they'd let others use the software?
>
> Jon
>
>
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