Archive | April, 2011

Pygmy Sundew Propagation by Gemmae

28 Apr

I recently ordered a number of carnivorous plants from Cook’s Carnivorous Plants as well as CP Jungle.  One of those plants was a pygmy sundew, Drosera Scorpioides.  I wasn’t sure what was going on with the top of the plant at first; was it flowering?  It was actually producing gemmae or brood bodies that may be propagated asexually.  These are modified leaves that break free in the wild when struck by rain and they each contain an exact clone of the parent plant.

Here is a 2.5 minute video showing my process for propagating my new Drosera scorpioides from gemmae:

 
This is the plant the same day it was received from Cook’s Carnivorous Plants:

Drosera scorpioides, a pygmy sundew

Drosera scorpioides, a pygmy sundew

I fed my plant a moth 2 days before removing about 5 of the gemmae, 2 of which you see in the video above.  For the morbidly curious, the video of the moth being enveloped by the sundew tentacles is below.  After about 30 seconds the footage is sped up to 2000% although you’ll still probably want to skip forward as there is a lot of footage.  Notice there are a few more gemmae on the plant in this video:

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Kinect + Blender 3D Scene Reconstruction

7 Apr

One of my current projects is to find a cheap and accurate way to 3D scan faces for the creation of custom coins and memorabilia;  mostly, I want my face on a 3D printable coin which can then be cast more cheaply in metal.  I had the opportunity to borrow a Microsoft Kinect which has 2 cameras and a structured light infrared laser projector.  One camera captures the infrared laser grid as projected into the room and constructs a depth map in realtime of the entire view.  The other camera captures visible light e.g. normal images and video.  I used the kinect to capture images and depth maps and reconstructed the scene in 3D using blender.  To dump the data, I used libfreenect‘s ‘record’ program, part of the OpenKinect project.

Here’s is a camera panning animation of the result created in blender using a displacement modifier on a heavily subdivided plane:

This is the unedited depth map that I took from the ‘record’ program output:

Kinect depth map produced by libfreenect's record utility

Kinect depth map produced by libfreenect's record utility

I had to scale and move the corresponding image texture to fit the geometry properly.  This is partly due to the slight distance between the cameras.  Here is the slightly altered texture image captured by the kinect:

Kinect image captured using libfreenect's record utility and slightly edited in gimp to align

Kinect image captured using libfreenect's record utility and slightly edited in gimp to align

This is the depth data as determined by blender’s ambient occlusion rendering:

Blender render showing depth via ambient occlusion

Blender render showing depth via ambient occlusion

I will soon compare these results to the free version of DAVID-laserscanner.  I’m currently waiting on the arrival of a very cheap laser line module ($2.50 to be exact) that will be used in conjunction with a high-def camera as input to the DAVID laserscanning software.  Stay tuned.

UPDATE: I’ve attached the .blend file for exploring in blender.  Textures are embedded.  Blender 2.56 Beta or later is recommended.

The Open Dream Journal Clip

1 Apr

I have wanted to design a simple notebook clip with an LED light for use on a dream journal for quite some time now.  Writing down dreams at night is difficult without a very convenient light source.  Now with access to a MakerBot 3D printer at sprout studios, I’ve released an open dream clip design on thingiverse, an online database of freely available and printable 3D models.  My design uses an LED and CR2032 battery, components commonly available at hackerspaces that would have 3D printers (and radioshack, although the parts are cheaper online through sites like digikey and mouser).

Here is the dream journal clip in action:

Dream Journal Clip with a white LED

Dream Journal Clip with a white LED

The first revision is pretty rough and we had to use tape on it to make it work:

Dream Journal Clip with a red LED

Dream Journal Clip with a red LED

Here is the MakerBot that Jimmie Rodgers kindly tuned and used to print the first test:

MakerBot at Sprout

MakerBot at Sprout

Planned improvements include:

  • using less plastic
  • making a larger hole for seating the LED
  • making a larger and deeper battery slot
  • adding a plastic tab to hold the battery in place (instead of tape)

Download the source files for the open dream clip on thingiverse and keep an eye out for  improvements shortly.