Boyz and their Toyz

[Redrobes]

Hey all, you have probably noticed that I have not been commenting and posting as much as usual and I have said that I have been busy making a new toy. Actually its sort of refurbishing an old toy but I know how you guys like a new toy so I thought I would show some pics.

A very long time ago...about 1994 I think it was but it might have been before that I got wind of a technique for getting 3D object data from laser scan lines. At the time this was really new stuff but I thought that this would become a well needed thing. In 1994 I was on the old Commodore Amiga - a great little machine - and it was used a lot for video work as it had a hardware genlock for video as an input. Anyway on the back of that came a lot of 3D rendering software and I thought that was very cool but it became really apparent really quickly that getting 3D objects into it was a real pain.

Out of a real skip (dumpster US sp ?) I got an old LP record deck and wired up some motors to it and got a video frame grabber and an old black and white vidicon tube security camera - i.e. this was done on a low low budget ! You could buy laser pointers for not too much and I made a line generator lens out of perspex because nobody sold them either.

The first results were poor but the principle was proven and since then every few years I seem to think of more ways to improve it. I have lost track of how many revisions its been through but its now using more up to date stuff and bigger motors and a better platter.

Well it all went into hibernation a while back for loads of different reasons but I wanted to revive it again. I should have had this capability for my Werthers skull challenge and missed it so I was determined to get it back online.

So my recent project and mass hacking is now complete with only some minor tweaks to put back in. God its faster than it used to be with modern PC's and oodles of RAM to hold the data.

So heres some pics. The original Cadbury's Episode 1 edition Darth Maul chocolates box sprayed white on the left showing the laser scan line running down it. Then the model in the middle after scanning. Note that the right part of his cloak has gone wrong as that is where the line gets hidden from the camera. You can fix that by taking two scans or using two cameras but this is the first scan data thats come out of it. And then pic three is the textured model using a texture that I had from years ago when I last did this model. (When SW Ep 1 was out I guess !). Ok its not all that well lined up but you get the gist.

I was digging through my box of models and came across a board with 3D terrain on it so I think I should be able to get some better starting models for my GTS by sculpting the basic shape. This should be able to make the rivers run approximately in the right places as its easier to sculpt a model than it is to guess the contours.

Hope you found that interesting.

[Gamerprinter]

I wouldn't mind having my own 3D scanner, but I lack the "jerry-rigging" skills to do what you're doing, Redrobes, very cool!

GP

[RPMiller]

Wow! That is very cool! Can you post pictures of the "toy" as well? I think that would be neat to see.

[Robbie]

Wow dood...I'd love to see the toy too...

and umm...wanna scan something for me?

[Steel General]

Pretty durn amazing, maybe you and some of your buddies should be on Junkyard Wars or I think they call Scrapheap Challenge? in Jolly Old

[NeonKnight]

Wow.

If you could figure out what a newb (like me) would need in standard purcahaseable parts and how to put thoe together, you could probably sell the plans. Or even better go to some computer company with your prototype and find a way to market the actual product. I know there are tonnes of techno geeks (like us) out there who would love to purchase such a toy for their own home use.

[Redrobes]

I'll post some more as I do a bit more work on it. I have been away from it but I will get a photo of it - probably tomorrow now. As for a list of parts and instructions, the principle is very very easy but as always the devil is in the details and there's a lot of devilish detail to be overcome.

Basically you get a laser which fires a small dot. You put that through a line generator lens and it makes that into a line as shown in the piccy. Then if you project that at the object but view it on the side and turn the lights out then the line wibbles left and right based on how far away the object is from the center. See first pic and look at the line, where its right the object has large radius, where its to the left the object has little radius. So take a lot of photos, rotating the object a little each time and you have a series of radial measurements of the object. So get PC to look at photos and convert those lines back into 3D, stitch up all the points into a 3D mesh and there you have it.

The hard part is trying to minimize all the noise. Since the camera needs to be just a little off to one side of the laser line then the wibble is really not all that much in the pics. So to get a good resolution of model you need to be tightly in control of any noise on the images. So laser line needs to be quite clean and very straight, images need to be clean and you need to make sure you don't lose accuracy in the conversion stages. You need a platter that rotates smoothly and accurately. With the original LP platter, any heavy object off center used to tilt the platter so that it would precess and cause all sorts of warp on the final model.

So the principle is easy but the actual implementation does require a certain amount of diligence and precision. Its the sort of thing where you cant afford to be sloppy but otherwise its no more difficult than any other thing.

[waldronate]

http://www.david-laserscanner.com/ might work for the lazy among us.

[Redrobes]

That david scanner looks cool and pretty simple to set up. Have you any experience of using it ? I can see how the calibration would work to get you camera field of view and so on. I would have thought that the position of the laser would make a difference. Perhaps it uses the line on the background printout to get the laser plane... anyway kudos to him for making that easy and cheap.

You were all asking for a pic of the set up so here it is. I took one today whilst faffing with it. Done a test scan of this mannequin head. I think I could get it better as it seems to be lacking in a bit of detail but I will progress it. On the left pic you can see the power supply, the stepper motor controller and the stepper driver on the top. That goes to the industrial sized stepper motor and toothed belt before going around the platter which is a big aluminum disk on bearings.

And Arcana, what did you have in mind to scan ?

EDIT -- thought id add a face height map for you Bryce / Leveller / Wilbur / etc / anyone else who can make use of it. (Im sure you can see where my dummy from the thatching thread came from now !)

[jezelf]

thats some pretty cool results you have there.

Further to what you were saying before about uses for this, I'm sure there are sculptors who would love to scan in their work for games or movies like over at

http://www.conceptart.org/forums/sho...d.php?t=134415

BTW- I like that face. Your height map of the face is one of those images you could see on a print to canvas image in a contemporary home.

Kinda reminds me of some canvas artwork I saw with a close up of a similar face, it was hand painted and a bit abstract but very nice.

I took the liberty of doing something similar to illustrate what I mean (hope you dont mind) for fun. ended up reminding me of those baby in the womb pictures - subtext of birth, new beginnings and 2001 and all that arty farty stuff.