Moai Models

One of my goals this summer was produce volumetric models for moai in order to determine center of mass and other physical parameters. Although $100K provides one the funds to purchase a 3D laser scanner, my approach was to do this using nothing more than a camera and photosynth. Using 100s of photos, www.photosynth.net, a point cloud extractor and some mesh editing software, this turned out to be laborious but possible. As a first step, I started with this photosynth of a statue that stands on a small ahu just a little ways from Tongariki.  

You will need to install a VRML plugin on your machine (see: http://cic.nist.gov/vrml/vbdetect.html) or (much preferred - MeshLab for which there is a mac, linux and windows version). But when you do, check out:

http://www.csulb.edu/~clipo/moai3.x3d or

http://www.csulb.edu/~clipo/moai3.3ds (and install MeshLab from http://meshlab.sourceforge.net)

I went from this (note that all the photos in the synth were taken in portrait mode and photosynth was unable to reconcile that fact with the landscape).

to this:

Zombies, Math and Modeling

Given the imminent threat of a zombie outbreak, it is good to know that some mathematicians/epidemiologists are taking zombies seriously. In Munz et al (2009) "WHEN ZOMBIES ATTACK!: MATHEMATICAL MODELLING OF AN OUTBREAK OF ZOMBIE INFECTION" recently published in an edited volume (Infectious Disease Modelling Research Progress) [and yes, the last author's last name really has a question mark at the end. see: http://www.mathstat.uottawa.ca/~rsmith/ ). According to their model, only quick aggressive attacks have a chance of staving off the end of the world. The abstract describes it all:

Zombies are a popular figure in pop culture/entertainment and they are usually

portrayed as being brought about through an outbreak or epidemic. Consequently,

we model a zombie attack, using biological assumptions based on popular zombie

movies. We introduce a basic model for zombie infection, determine equilibria and

their stability, and illustrate the outcome with numerical solutions. We then refine the

model to introduce a latent period of zombification, whereby humans are infected, but

not infectious, before becoming undead. We then modify the model to include the

effects of possible quarantine or a cure. Finally, we examine the impact of regular,

impulsive reductions in the number of zombies and derive conditions under which

eradication can occur. We show that only quick, aggressive attacks can stave off the

doomsday scenario: the collapse of society as zombies overtake us all.

This graph says it all:

Zombies, ants, and fungi

For those of you just about to sit down to enjoy a bowl of wild mushroom risotto, you might consider the potential consequences....

http://www.scientificamerican.com/article.cfm?id=fungus-makes-zombie-ants

synthy synths from Easter Island 2009

More synths for the viewing per square meter than any other blog around. All that I've done can be found here: http://photosynth.net/UserProfilePage.aspx?user=clipo&content=Synths

Puna Pau: the hat quarry -- http://photosynth.net/view.aspx?cid=818c127b-d00c-4dba-a398-21272605de17

Moai at Rano Raraku -- http://photosynth.net/view.aspx?cid=3c2daf90-cdcc-42fb-a91f-8e3f2057af21

Tongariki -- http://photosynth.net/view.aspx?cid=1a605039-e964-4b87-aa91-e6c8f777a261

Pukao at Tongariki -- http://photosynth.net/view.aspx?cid=0dd2f6cf-a9b4-4906-bc4e-d464f5d97d8a

Road Moai along South Coast -- http://photosynth.net/view.aspx?cid=f895e1a6-cb75-4a24-b136-c79ee44d48eb

Road Moai at Vai Mata -- http://photosynth.net/view.aspx?cid=f0f45b30-9dac-4073-bbc1-7e06b005143a

Vinapu -- http://photosynth.net/view.aspx?cid=e59fb781-1072-4965-b06a-9bea8e19252e

Fallen Moai II

This photosynth was created for one of the road moais on the south coast a little past Akahanga. The statue fell on its back so the front surface is more visible than the previous synth at Vai Mata.

http://photosynth.net/view.aspx?cid=F895E1A6-CB75-4A24-B136-C79EE44D48EB

Fallen Moai

Part of our analyses here on Rapa Nui consist of observing moai in their various forms -- at the quarry, in the roads, on the ahus. There are a number of attributes related to the technology of carving, transporting and displaying the statues that can be discerned - a fact I puzzle over given the lack of previous acknowledgement and abundant crazy speculation. To paraphrase: "What were they thinking when they described the moai?"

Anyways to help document some of these things, I created a photosynth of one of the "fallen" moai that failed during transport (or at least that is my current hypothesis). This synth worked out fairly well and has a lot of good detail about moai morphology (click the ctrl key to see the point cloud).

http://photosynth.net/view.aspx?cid=F0F45B30-9DAC-4073-BBC1-7E06B005143A

Ahu Vai Mata - NW Coast of Easter Island

Check out the various patterns of the sea wall construction.