Monthly Archives: March 2010

3D Scanner – ExtraMini Update

Just finished a pretty sketchy algorithm to fill in the holes left by scanning errors so i can now create surfaces on the models. Been hittin the JW red label while coding in celebration of the purchase of some wheels, so can’t be bothered to write an explanation of how it works just yet.

Here is a picture of a full model, algorithm isn’t perfect, needs more work. But for now it gives a fairly rough but almost respectable skinned model.

Skinned 3D model

I think a lot of the nosie issues are related to the laser line being to diffuse. Gonna try and do something about that, not sure what yet.

3D Scanner – Mini Update “Scan Time!!”

It works!!

Admittedly not so well, but….it works!! still a lot of tweaking to do on the software side, need to work out a good way to add a skin to the model and need to tweak the spline finding algorithm a bit.  I’ll be  doing a bigger post later with the final mods to the scanner body and releasing the code.

The First Scan

The object that was scanned and the model produced side by side.

It’s quite hard to see all the features on a static  view of the model, but when you can rotate it round it you can see quite a few of the smaller details. Hopefully when it’s skinned some more of the details will be visible.

Bonus shot of the scanner with added bonus of my feet.

The Scanner

3D Scanner Part 2 – Wherein things begin to go wrong

So after spending most of the weekend re-writing and working on the code to extract the 3D models the hard-drive on my main PC gave out the clunk of death. Which kinda sucks. When I’ve got a free day I may have a go at recovering some stuff, but for now I’m going to cut my losses and start rewriting it from scratch. Now that I’ve got an idea what I’m doing it shouldn’t take to long.
For now here are some photos of the progress on the hardware side of the project.

WordPress lost all the info I entered into the gallery, and I can’t be bothered to re-enter it. So here’s a brief overview of what I’ve done.

  • Sprayed inside of scanner body black to reduce ambient light.
  • Mounted the unmodified laser line generator into the body.
  • Took out the laser line generator and split it into 2 separate modules (and built in current limiting resistors so they can operate at 5V) so I could build another scanner at some point (I’m thinking a room scanner would be kinda cool).
  • Wrote some Arduino code and built a circuit to control the stepper motor underneath the rotating platform (Code and schematics will be posted soon, both are incredibly simple).
  • Realised stepper motor sucks and I need a better one.

Getting pretty close to finishing now and next week I’m off for 2 weeks so hopefully things should be all wrapped up soon and I’ll be 3D scanning to my hearts content.

(Side note: For large datasets created with 3D scanners Meshlab looks like an awesome tool ,had a quick play around and despite some mild difficulty compiling it’s fairly straight forward to use.).

3D Scanner – Mini Update “Freakin Lasers!”

Small update on the laser scanner project. I’ve got 100% more lasers!

Laser in Scanner

Here's a picture of the laser line generator inside the scanner.

Didn’t think I could get so excited about lasers, but this little contraption for marking lines on walls is pretty cool.

Laser Line Generator

The laser line generator

All that’s left to do now is build the electronics to control the stepper motor that rotates the platform and mount the webcam and line generator inside the scanner body.
I also may do a little bit of spray painting and probably re-write a fairly hefty chunk of the control software to make it a bit more user firendly.

Bad Haikus & Broken Images

Oh, dear images
Why have you left my blog now?
Please will you come back

Edit #1:

So sky is to blame
Damn your poor broadband service
Damn Rupert Murdoch

Quick Hack: IR Webcam

It’s been done multiple times before, but here’s a quick hack to create an infra-red webcam.

Infra-red Bed Lamp

Infra-red image of my bedside Lamp

There are some slightly odd artefacts in the above image (the dark blotches towards the left of the image), possibly caused by directly exposing the camera sensor to light (they appear to be blurry images of part of the internals of the sensor). This has happened before and tends to go away after a while, I’ll be honest I’ve got no idea what’s really going on there.

All (at least all I’ve ever come across) webcam CCD’s can ’see’  infra-red light, but have a filter on them to block it out. The actual hack is incredibly simple, although may vary depending on your model of webcam.

  • Unscrew lens.
  • Remove infra-red filter. In my case this was a small glass square that I was able to remove by breaking it.
  • Cut a small square from a floppy disk (floppy disk platters act like pretty good visible light filters).
  • Place floppy disk filter where the infra-red filter was.
  • Re-screw lens.

Here are a couple of photos of the cameras internals, and the lens removing process.

Camera With Lens Removed

Lens, Infa-red Filter & Visible Light Filter

And one final image just to prove it’s infra-red, here is a picture of the infra-red LED from a TV remote and the light from our living room.

Remote and Light

This may get used for the 3D scanner if I can find a CD burner to dismantle for the infra-red laser diode.

3D Scanner Part 1 – Hardware

This afternoon I decided to start work on the hardware side of a 3D scanner project I wrote the software for a while ago.

Here are a few things i learnt while making this:

  • Woodwork is awesome and I want to start doing more.
  • I’m not very good at woodwork.
  • Splinters from cheap plywood hurt like a b*stard.
  • Drilling bits of aluminium too fast makes them mildly weld to the drill bit and spin around cutting parts of your fingers

I’m going to be trying to use this blog as a build log as I go along with the hope of writing it up as an instructable when I’m done. I’ll also post some theory behind how the scanner works once the physical build is finished.