The idea came to me, and I tried it.
It works.
Useful when you need a .dxf of an odd-shaped item for routing, e-
mailing etc.
The grid is a diffuser for suspended ceiling fluorescent lighting
fixtures.
The grid spacing, in this case, is in mm and easily scaled.
This one was for a customer who wanted to use this sink because it fit
her cabinet.
It could be used for lots of things, I think.
http://i123.photobucket.com/albums/o290/Robatoy/Gridtrace.jpg
On May 30, 5:23=A0pm, Robatoy <[email protected]> wrote:
> On May 30, 3:17=A0pm, RicodJour <[email protected]> wrote:
>
> > Right. =A0Since you'd have to know the grid size and size the picture t=
o
> > make it work, wouldn't it be just as easy to take the picture, with a
> > straight rule in frame, and then overlay an appropriately dimensioned
> > grid in SketchUp, then export the DXF?
>
> If you know how much barrel/pincushion distortion your camera lens
> creates, sure.
Well, I guess that's true of any lens - you have to know it's
limitations and compensate for them. You've taken a step in the right
direction. You're in the jet age, but I think you need to join the
space age:
http://www.jvrb.org/archiv/1275/index_html?set_language=3Dde&cl=3Dde
http://www.spgdata3d.com/spg_yours_applications.php
> That rule-in-the-picture trick, used since the daguerreotype days, is
> very limited in accuracy.
Why? And put a number on "very limited". If it's a fixed focal
length lens and you have two rulers, I don't see any real world
difference in accuracy between the diffuser grid and the rulers.
'cept I usually have a couple rulers laying around and a ruler's line
marking are easier to determine than a diffuser's edges.
R
On May 30, 9:32=A0pm, Robatoy <[email protected]> wrote:
>
> Ahh... TWO rules... that's better.
I thought it was "And one ring to rule them." ;)
I still don't quite follow why you think a rule in a picture is
inaccurate. Please elaborate.
R
On May 30, 9:09=A0pm, RicodJour <[email protected]> wrote:
> On May 30, 5:23=A0pm, Robatoy <[email protected]> wrote:
>
> > On May 30, 3:17=A0pm, RicodJour <[email protected]> wrote:
>
> > > Right. =A0Since you'd have to know the grid size and size the picture=
to
> > > make it work, wouldn't it be just as easy to take the picture, with a
> > > straight rule in frame, and then overlay an appropriately dimensioned
> > > grid in SketchUp, then export the DXF?
>
> > If you know how much barrel/pincushion distortion your camera lens
> > creates, sure.
>
> Well, I guess that's true of any lens - you have to know it's
> limitations and compensate for them. =A0You've taken a step in the right
> direction. =A0You're in the jet age, but I think you need to join the
> space age:http://www.jvrb.org/archiv/1275/index_html?set_language=3Dde&cl=
=3Dde
>
> http://www.spgdata3d.com/spg_yours_applications.php
>
> > That rule-in-the-picture trick, used since the daguerreotype days, is
> > very limited in accuracy.
>
> Why? =A0And put a number on "very limited". =A0If it's a fixed focal
> length lens and you have two rulers, I don't see any real world
> difference in accuracy between the diffuser grid and the rulers.
> 'cept I usually have a couple rulers laying around and a ruler's line
> marking are easier to determine than a diffuser's edges.
>
> R
Ahh... TWO rules... that's better.
On May 30, 10:28=A0pm, Robatoy <[email protected]> wrote:
> On May 30, 9:39=A0pm, RicodJour <[email protected]> wrote:
> > On May 30, 9:32=A0pm, Robatoy <[email protected]> wrote:
>
> > > Ahh... TWO rules... that's better.
>
> > I thought it was "And one ring to rule them." =A0;)
>
> > I still don't quite follow why you think a rule in a picture is
> > inaccurate. =A0Please elaborate.
>
> For openers, you'd have to be sure that the rule is perfectly planar
> to your imaging device, and that the second rule is coordinated with a
> known angle (usually 90-degrees), also planar to the imaging device.
Not exactly an insurmountable problem - I could probably scare up a
square, use a newspaper or do any number of other things to get a 90.
As far as the planar issue, how is that different than the diffuser?
That's an issue with any photographic measurement technique.
A steel rule is less than 1/16" of an inch thick - for all intents
flat. Not so with a diffuser. A diffuser has depth that won't help
the situation. The center of your photograph with the diffuser will
be normal to the lens, but the further from the center the bigger the
distortion with a grid that has an appreciable thickness.
> All of this is old hat, btw.http://www.etemplatesystem.com/Portals/37/etp=
hoto%20brochure.pdf
> My little grid helper will be useful to some.
No doubt, I'm not arguing that. It's quick and more than reasonably
effective for a down and dirty grid layout. I'll keep my eyes open
for a diffuser getting tossed.
R
On May 30, 9:03=A0am, Robatoy <[email protected]> wrote:
> On May 30, 8:47=A0am, RicodJour <[email protected]> wrote:
> > On May 30, 1:51=A0am, Robatoy <[email protected]> wrote:
>
> > > The idea came to me, and I tried it.
> > > It works.
>
> > > Useful when you need a .dxf of an odd-shaped item for routing, e-
> > > mailing etc.
> > > The grid is a diffuser for suspended ceiling fluorescent lighting
> > > fixtures.
> > > The grid spacing, in this case, is in mm and easily scaled.
>
> > > This one was for a customer who wanted to use this sink because it fi=
t
> > > her cabinet.
> > > It could be used for lots of things, I think.
>
> > >http://i123.photobucket.com/albums/o290/Robatoy/Gridtrace.jpg
>
> > That's just a plain white grid diffuser? =A0Not a bad idea. =A0All I ha=
ve
> > around here are the parabolic reflector diffusors, which probably
> > wouldn't work as well.
>
>
> It is a clear one, but I think a white one would work too.
Right. Since you'd have to know the grid size and size the picture to
make it work, wouldn't it be just as easy to take the picture, with a
straight rule in frame, and then overlay an appropriately dimensioned
grid in SketchUp, then export the DXF?
R
On 5/30/2009 12:17 PM RicodJour spake thus:
> On May 30, 9:03 am, Robatoy <[email protected]> wrote:
>
>> On May 30, 8:47 am, RicodJour <[email protected]> wrote:
>>
>>> On May 30, 1:51 am, Robatoy <[email protected]> wrote:
>>
>>>> The idea came to me, and I tried it.
>>>> It works.
>>
>>>> Useful when you need a .dxf of an odd-shaped item for routing,
>>>> e- mailing etc. The grid is a diffuser for suspended ceiling
>>>> fluorescent lighting fixtures. The grid spacing, in this case,
>>>> is in mm and easily scaled.
>>
>>>>http://i123.photobucket.com/albums/o290/Robatoy/Gridtrace.jpg
>>
>>> That's just a plain white grid diffuser? Not a bad idea. All I have
>>> around here are the parabolic reflector diffusors, which probably
>>> wouldn't work as well.
>>
>> It is a clear one, but I think a white one would work too.
>
> Right. Since you'd have to know the grid size and size the picture to
> make it work, wouldn't it be just as easy to take the picture, with a
> straight rule in frame, and then overlay an appropriately dimensioned
> grid in SketchUp, then export the DXF?
Ackshooly, I could do that with my old copy of Corel Draw. Probably even
with my lowly little Paint Shop Pro.
--
Found--the gene that causes belief in genetic determinism
On May 30, 11:14=A0pm, RicodJour <[email protected]> wrote:
> On May 30, 10:28=A0pm, Robatoy <[email protected]> wrote:
>
> > On May 30, 9:39=A0pm, RicodJour <[email protected]> wrote:
> > > On May 30, 9:32=A0pm, Robatoy <[email protected]> wrote:
>
> > > > Ahh... TWO rules... that's better.
>
> > > I thought it was "And one ring to rule them." =A0;)
>
> > > I still don't quite follow why you think a rule in a picture is
> > > inaccurate. =A0Please elaborate.
>
> > For openers, you'd have to be sure that the rule is perfectly planar
> > to your imaging device, and that the second rule is coordinated with a
> > known angle (usually 90-degrees), also planar to the imaging device.
>
> Not exactly an insurmountable problem - I could probably scare up a
> square, use a newspaper or do any number of other things to get a 90.
> As far as the planar issue, how is that different than the diffuser?
> That's an issue with any photographic measurement technique.
>
> A steel rule is less than 1/16" of an inch thick - for all intents
> flat. =A0Not so with a diffuser. =A0A diffuser has depth that won't help
> the situation. =A0The center of your photograph with the diffuser will
> be normal to the lens, but the further from the center the bigger the
> distortion with a grid that has an appreciable thickness.
>
> > All of this is old hat, btw.http://www.etemplatesystem.com/Portals/37/e=
tphoto%20brochure.pdf
> > My little grid helper will be useful to some.
>
> No doubt, I'm not arguing that. =A0It's quick and more than reasonably
> effective for a down and dirty grid layout. =A0I'll keep my eyes open
> for a diffuser getting tossed.
>
> R
This 2 x 4 foot diffuser was 8 bucks. HD, new.
On May 30, 9:39=A0pm, RicodJour <[email protected]> wrote:
> On May 30, 9:32=A0pm, Robatoy <[email protected]> wrote:
>
>
>
> > Ahh... TWO rules... that's better.
>
> I thought it was "And one ring to rule them." =A0;)
>
> I still don't quite follow why you think a rule in a picture is
> inaccurate. =A0Please elaborate.
>
> R
For openers, you'd have to be sure that the rule is perfectly planar
to your imaging device, and that the second rule is coordinated with a
known angle (usually 90-degrees), also planar to the imaging device.
All of this is old hat, btw.
http://www.etemplatesystem.com/Portals/37/etphoto%20brochure.pdf
My little grid helper will be useful to some.
Robatoy wrote:
> The idea came to me, and I tried it.
> It works.
>
>
> Useful when you need a .dxf of an odd-shaped item for routing, e-
> mailing etc.
> The grid is a diffuser for suspended ceiling fluorescent lighting
> fixtures.
> The grid spacing, in this case, is in mm and easily scaled.
>
> This one was for a customer who wanted to use this sink because it fit
> her cabinet.
> It could be used for lots of things, I think.
>
> http://i123.photobucket.com/albums/o290/Robatoy/Gridtrace.jpg
Ooo! Clever.
On May 30, 8:47=A0am, RicodJour <[email protected]> wrote:
> On May 30, 1:51=A0am, Robatoy <[email protected]> wrote:
>
> > The idea came to me, and I tried it.
> > It works.
>
> > Useful when you need a .dxf of an odd-shaped item for routing, e-
> > mailing etc.
> > The grid is a diffuser for suspended ceiling fluorescent lighting
> > fixtures.
> > The grid spacing, in this case, is in mm and easily scaled.
>
> > This one was for a customer who wanted to use this sink because it fit
> > her cabinet.
> > It could be used for lots of things, I think.
>
> >http://i123.photobucket.com/albums/o290/Robatoy/Gridtrace.jpg
>
> That's just a plain white grid diffuser? =A0Not a bad idea. =A0All I have
> around here are the parabolic reflector diffusors, which probably
> wouldn't work as well.
>
> R
It is a clear one, but I think a white one would work too.
On May 30, 11:46=A0pm, Robatoy <[email protected]> wrote:
> On May 30, 11:14=A0pm, RicodJour <[email protected]> wrote:
>
> > I'll keep my eyes open for a diffuser getting tossed.
>
> This 2 x 4 foot diffuser was 8 bucks. HD, new.
I'm never going to use it, so I don't want to pay for it. =3D:O
R
On May 30, 3:17=A0pm, RicodJour <[email protected]> wrote:
> On May 30, 9:03=A0am, Robatoy <[email protected]> wrote:
>
>
>
> > On May 30, 8:47=A0am, RicodJour <[email protected]> wrote:
> > > On May 30, 1:51=A0am, Robatoy <[email protected]> wrote:
>
> > > > The idea came to me, and I tried it.
> > > > It works.
>
> > > > Useful when you need a .dxf of an odd-shaped item for routing, e-
> > > > mailing etc.
> > > > The grid is a diffuser for suspended ceiling fluorescent lighting
> > > > fixtures.
> > > > The grid spacing, in this case, is in mm and easily scaled.
>
> > > > This one was for a customer who wanted to use this sink because it =
fit
> > > > her cabinet.
> > > > It could be used for lots of things, I think.
>
> > > >http://i123.photobucket.com/albums/o290/Robatoy/Gridtrace.jpg
>
> > > That's just a plain white grid diffuser? =A0Not a bad idea. =A0All I =
have
> > > around here are the parabolic reflector diffusors, which probably
> > > wouldn't work as well.
>
> > It is a clear one, but I think a white one would work too.
>
> Right. =A0Since you'd have to know the grid size and size the picture to
> make it work, wouldn't it be just as easy to take the picture, with a
> straight rule in frame, and then overlay an appropriately dimensioned
> grid in SketchUp, then export the DXF?
>
> R
If you know how much barrel/pincushion distortion your camera lens
creates, sure.
That rule-in-the-picture trick, used since the daguerreotype days, is
very limited in accuracy.
On May 30, 1:51=A0am, Robatoy <[email protected]> wrote:
> The idea came to me, and I tried it.
> It works.
>
> Useful when you need a .dxf of an odd-shaped item for routing, e-
> mailing etc.
> The grid is a diffuser for suspended ceiling fluorescent lighting
> fixtures.
> The grid spacing, in this case, is in mm and easily scaled.
>
> This one was for a customer who wanted to use this sink because it fit
> her cabinet.
> It could be used for lots of things, I think.
>
> http://i123.photobucket.com/albums/o290/Robatoy/Gridtrace.jpg
That's just a plain white grid diffuser? Not a bad idea. All I have
around here are the parabolic reflector diffusors, which probably
wouldn't work as well.
R