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Greybeard
12-07-2006, 11:49 AM
Just to keep you up to date on what I'm up to over on this side of the pond, I've attached some pics of my endeavours.

I covered a small metal casting with a dilute milk solution and photographed it.
My basic oversight was that while the milk added a "greyscale" effect to the picture, it also blurred out the lower detail.
I'll soon post my next development which is to try the same setup, but with a clear coloured liquid, and extract the colour density as a function of depth.
John

Greybeard
12-07-2006, 02:49 PM
Here's my latest trial. Same piece but sprayed matt white(not very successfully - the top lines broke through the paint and are still dark), then immersed in mouthwash ! The original is about 1/8 deep by the way, and roughly 2" x 2".
Flash photo, imported into Corel Photopaint, the contrast increased and converted to 8 bit greyscale. Exported to Designer as before.

I can see the possibilities now, and think the nextstep is to try a much higher concentration of colour than the mouthwash had. I'll probably try a spirit dye for the next test.

Greybeard
12-08-2006, 05:24 PM
4" tall plastic figure immersed in a black dye bath. There was considerable dust on the surface of the liquid which the flash picked up, so a small amount of editing before importing it into Designer.
John

goz
12-08-2006, 06:59 PM
For 3D scanning at work I use a white talc spray called "Magna Flux".

It is used for checking welds for cracks and imperfections. Can be found at most welder supply locations. In a pinch..aftate foot spray also coats with a nondestructive white talc that can be wiped off post scan. Eliminating glare spots from flash and ambient lighting helps greatly to emulate a greyscale depth image.
There is a reasonable 3D scanner for less than $3000.00 at nextengine.com. As a user of a high end scanner I am impressed by the resolution that this low priced unit provides. Any 3D polygon scan can be rendered into a greyscale depth image providing a true relief carving result.

Greybeard
12-09-2006, 03:02 AM
Thanks for the info goz. Unfortunately, with my pension giving me about $7000 annualy, that scanner is somewhat out of reach.

I can see that I might improve matters greatly by working on the lighting setup to avoid the use of flash, so I'll be looking at that next.

John

wunderkind
12-27-2006, 05:05 PM
Thanks for the trials John. Converting 2D to 3D sounds like it should be a breeze but I bet that you'll figure it out. Lots of trials that wish I had time for. But in reality every 2D picture is of a 3D subject so it should be possible. Looking Good Though.
Jim

DougM
01-22-2007, 08:03 AM
Howdy all, I just bought a carvewright and I am loving it. I have been going thru the forums to catchup on all the hints and tips I can learn. I run a hand crafted pen making website and have had to deal with the lighting issues you have talked about when photographing my pens. I found a website called www.lastolite.com which has some wonderful products for dealing with lighting issues. I use the Ephoto kit myself http://www.lastolite.com/ephotomaker.php since the products I make are rather small (hoping to expand now with the carvewright!). You can see what some of my results are like in my gallery at www.mutzigcreations.com

If you don't want to buy a light tent you can also make one. Here is a site that shows you several different types and how to make them http://www.creativepro.com/story/feature/19002.html or just do a google search for "how to make a light tent" you'll def. find something you like with that no matter how big an item you are trying to capture and image of.

There was also an article in Woodturning design (winter 2007) dealing with photographing items to cut down on glare, etc... If you want I can scan it and post it either here or on my site.

Doug

HandTurnedMaple
01-22-2007, 10:44 AM
That light tent info looks really useful and definately budget-friendly (what's cheaper than a box of Kleenex). Thanx.

Greybeard
01-22-2007, 12:18 PM
Thanks Doug for that link.
I've temporarily moved over to trying a scanner with the object in a small tank of wine!(my elderberry this year is pretty dense in colour)
Doing this I discovered serious barrel(?)distortion with depth on my scanner, even though the depth of focus isn't too bad - about 1".

I think I'll go back to the camera and continue in that direction.
Regards
John

DougM
01-22-2007, 01:27 PM
Glad to help,

On the barrel distortion issue.. I know of a plug-in for Photoshop that can do corrections along those lines (like the fish bowl effect you get with some types of lenses). hmmmm don't recall the name right off the bat but I know I have it around here some where...I'll see what I can find and post it up here.

Doug

Greybeard
01-22-2007, 01:41 PM
Thanks Doug.
What sent me to the scanner was the lighting + dust on the liquid surface + poor depth of focus from the lack of attention I gave to my set up.
The idea of using the scanner was to remove the first two, by viewing from underneath, and a trial run showed that though the depth of focus was ok, the field of view was badly distorted.
I think that if I were then to use software to remove that, I'd then be introducing an additional complication, and the remit I gave myself at the beginning was to come up with a system that would be simple.
It had to be based on the sort of kit that most people might have, and just be an ingenious use of it.
I now think that if I'd paid more attention to my set up with the camera I can get round the difficulties.
However, the dozen or so other projects keep getting in the way and fighting for my attention.
I'm sure you know how it is.
Regards
John

DougM
01-22-2007, 02:07 PM
LOL, Aye I do know! I have to keep a book just to keep track of all the projects...now if I could just finish a couple that would be something!

Let me know how it turns out as I am most interested (though I won't tell my wife about the use of wine...she would think it total wine abuse LOL.

Doug

Justin
01-23-2007, 02:57 AM
Great work. I've been thinking about making a setup like this, your work really helps in that respect. Thanks.

Another thought regarding low cost scanning - I have a hunch that the $300 scanning probe is not much more than a feather-touch pressure switch wired directly to that standard mono audio jack. A bit adaptor is only $4, I think I could build a pretty good probe onto one for a few dollars more, making a $10 scanning probe (plus labour time :-). If I understand it correctly, there doesn't seem to be a need for the probe to have graded pressure feedback, so I'm guessing it's on/off, and if so, the device may well be both electrically and mechanically trivial. Coming up with a homebrew construction that would stand up to the rigours of rapid scanning and maintain precision without damaging the surface would not be so trivial, but I'm sure there will be an easy and widely accessable construction solution that a little R&D can find.

More to the point, if we reverse engineer the probe, can anything other than a scanning head be built? Maybe some kind of colour marker plotter-like system to print an image onto a sculpture (this would need some software alteration though). Maybe a probe that makes no physical contact with the surface, or a probe based on emitting and detecting bounched light so that surface colour affects the recorded height... which is very much a solution searching for a problem, because I can't think of a use for it :) Maybe in conjunction with magnifying optics, it could up-scale the recorded depth of the texture, allowing for scanning a 3d surface where the texture is too shallow for point contact to produce useful results.

Greybeard
01-23-2007, 03:55 AM
Hi Justin, and thanks for your input.
If your interested in diy probes google "cnczone" and "probes". There's been a lot of work done there.
Regards
John

HighTechOkie
01-23-2007, 12:55 PM
I did some searching on google for "diy 3d scanner". There are a handfull of home brew solutions. One of the most interesting and inexpensive for our purposes is found here:

http://www.cs.tu-bs.de/rob/david.html

I'm thinking if you couple this with an inexpensive HD camcorder like the Sanyo HD1a, you could capture at 1280x720. Pretty interesting stuff and simple to try with your current webcam.

I also found http://www.3d3solutions.com/flexscan3d.php but they want $1499 for their software. It might be an option if a few people wanted to chip in. We could then host this software so everyone could import their own photos to generate the point cloud. Definitetly some hurdles to overcome with this option.

Rob

Greybeard
01-23-2007, 02:14 PM
Hi Rob.
Yes, I've been aware of the David forum for some time, in fact you will spot my handle in quite a lot of the postings :D

I've done a couple of trials with my own kit, and I shall continue to keep an eye on developments there, especially if they produce their own stitching facility in the software.

Mind you, like so many other things I have on my plate, I'm not sure where that particular interest will take me .
It seems the more I learn, the more I want to know !
I expect my epitaph to be "He's on his final project now".
Regards
John

HandTurnedMaple
01-23-2007, 04:42 PM
I did some searching on google for "diy 3d scanner". There are a handfull of home brew solutions. One of the most interesting and inexpensive for our purposes is found here:

http://www.cs.tu-bs.de/rob/david.html

I'm thinking if you couple this with an inexpensive HD camcorder like the Sanyo HD1a, you could capture at 1280x720. Pretty interesting stuff and simple to try with your current webcam.
Rob

So I'm looking at this, thinking what an absolutely incredible piece of software for being freeware. And then I realized why it's free. On the Screenshots window they are scanning in a bust sculpture. But on the 3D results, its a kneeling cherub. So if I scanned in one of my numerous eagle sculpture decorating my den, would scan in as an ostrich? :shock:

Dan-Woodman
01-23-2007, 05:33 PM
How about a glass etching head that would follow a paper pattern from your printer --scanner.

Greybeard
01-23-2007, 05:37 PM
Er, 2D/3D ? Like to flesh that one out a little Dan ?

Regards
John

Dan-Woodman
01-23-2007, 05:43 PM
I just need 2 deer head w-antlers faceing each other to put on the doors of a large gun cabinet I'm making .
It would be nice if this machine would do glass etching. But I think thats asking a little much.

Greybeard
01-23-2007, 05:57 PM
Right Dan, not what the thread's about, but how about this for a method.
Take one layer of wood 1" thick of a suitable size for your design. then spray with a light layer of adhesive spray. Lay on a sheet of thin vinyl plastic, say.008" thick, and respray with more adhesive. Lay on top of that a 1/8" MDF or thinner ply if you can get it.

Cut out your pattern with the bit just going down into the bottom layer.
Remove top layer, peel off vinyl and you have a stencil for a glass etch.

With luck you'll have a residue of adhesive on the vinyl to position each piece onto the glass.

That's the best I can come up with. :)
Regards
John

HighTechOkie
01-23-2007, 08:23 PM
I hadn't checked the forum over there. Good to know we have someone with experience playing with DAVID, even if it has its limitations.

Rob

wolfvonstk
01-31-2007, 06:27 AM
here is a product i have been useing for years. its D-Sculptor , you can google D Vision. there on version 2 now witch is better but a or so ago one of the 3d mags had vesion 1 for free. it may still be in there . all you do is print out a paper with circals on it ,put object in center and take photos. then you pinpoint the dots in the phots and do a little outlineing. then the program gives you a 3d object that can be expoted to 3d studios or auto cad.


any one who would like to share a projut or two with me thanks

wolfvonstk@aol.com

wolfvonstk
01-31-2007, 06:27 AM
here is a product i have been useing for years. its D-Sculptor , you can google D Vision. there on version 2 now witch is better but a or so ago one of the 3d mags had vesion 1 for free. it may still be in there . all you do is print out a paper with circals on it ,put object in center and take photos. then you pinpoint the dots in the phots and do a little outlineing. then the program gives you a 3d object that can be expoted to 3d studios or auto cad.


any one who would like to share a projut or two with me thanks

wolfvonstk@aol.com

menewfy
01-31-2007, 09:55 PM
[quote="wolfvonstk"]here is a product i have been useing for years. its D-Sculptor , you can google D Vision. there on version 2 now witch is better but a or so ago one of the 3d mags had vesion 1 for free. it may still be in there . all you do is print out a paper with circals on it ,put object in center and take photos. then you pinpoint the dots in the phots and do a little outlineing. then the program gives you a 3d object that can be expoted to 3d studios or auto cad.


any one who would like to share a projut or two with me thanks

can you please upload an example of this both the pic and the result.
thanks

Jeff_Birt
02-03-2007, 12:59 PM
Using the links about home made lighting tents in this thread I contructed one out of a cardboard box and tissue paper this morning. The results were pretty good considering it cost nothing. I think I will try sloping the sides to get more downward lighting. The color is a bit off,even when tweaked but I have an OLD digital camera.

Greybeard
02-03-2007, 03:01 PM
Jeff - is the jpeg you've posted, the photo you took in the tent, or a photo of the carving you did, from a photo you took in the tent ?

(Good grief, can you understand that ? :) )

Regards
John

Greybeard
02-03-2007, 04:54 PM
here is a product i have been useing for years. its D-Sculptor , you can google D Vision. there on version 2 now witch is better but a or so ago one of the 3d mags had vesion 1 for free. it may still be in there . all you do is print out a paper with circals on it ,put object in center and take photos. then you pinpoint the dots in the phots and do a little outlineing. then the program gives you a 3d object that can be expoted to 3d studios or auto cad.


any one who would like to share a projut or two with me thanks

wolfvonstk@aol.com

Hi Wolf. I've googled d sculptor, and followed a few 3 year old leads, but got no further in trying to find the version1 you mentioned.
As I don't have a spare £500 for the standard version 2, I'd be interested in learning more about that method.
Regards
John

Jeff_Birt
02-03-2007, 05:04 PM
John, It's a photo of a carving I did. I took the photo in the light tent.

gyroplane
02-05-2007, 10:49 PM
Here is a method for creating displacement maps using only a digital camera and a flashlight (and some free software).

http://zarria.net/

I have not used it, but it looks interesting. If anyone tries it, please post the results.
-Sky

Greybeard
02-06-2007, 03:22 AM
Sky - thanks for the link.
Someone else sent me to that page last year, and I had a look, but never followed it up.
This time I will, having learned a little more since then, so thanks again for the link.
I'm thinking of lookin at combining elements from that idea with some from other methods, and will post if it seems promising.
Meanwhile back to work.

John