Kinect 3D outdoor: first test

It was a sunny September Sunday, so I decided to take a walk with my wife Kathi and show her one of the hermitages located in the valley in which we live (Val di Non, Trentino, Italy). 

My second thought was that the ramble was a perfect opportunity to test the hacked Kinect and try to document in 3D the main wall of S. Gallo's ruins (the remains of the hermitage). So I prepared the backpack with Kinect, the external battery and the rugged pc we normally use on the archaeological excavations. 

After half an hour's walk throught apple orchards and woods we reached the hermitage. Along the way we also found a stunned rooster. That was strange! A rooster, in italian "gallo", in the S. Gallo's hermitage...

However, we began to try to document the main wall of the ruins, which you can see in the picture below...

S. Gallo's hermitage, with the rooster

... but, probably due to direct sunlight conditions, Kinect and RGBDemo where not working propertly.

In fact, as you can also read in M. Dalla Mura, M. Aravecchia and M. Zanin poster (during "LOW COST 3D: sensori, algoritmi e applicazioni" workshop), "...The main issue is due to direct Sun illumination that leads to saturation in the depth acquisition...". Moreover the software (RGBDemo) was reacting very slowly, but this was probably due to the hardware (Panasonic Thougbook), which is less powerful compared to the laptop I normally use to work. Secondly also RGBDemo seems to work better on GNU/Linux (ArcheOS), the Operating System which runs my laptop, than in Windows, the rugged PC OS (but this could be just my impression). 

Not beeing satisfied with the results I get with the 3D documentation of the ruins (software too slow to manage all the data recording process, high errors on the sunny parts of the wall, etc...), I decided to check for another subject to document. Luckily in S. Gallo's hermitage are not missing the caves, so, with the help of Kathi, I did a fast digital 3D copy of the cave you see in the picture below.

S. Gallo's cave

This time the software was working good, fast enought to work on the field and with negligible errors in data acquiring. In the movie below it is possible to see the final pointcloud (not complete, but big enought to understand the quality of a 3D "field" documentation with Kinect).

After this test, our Kinect was ready to the "trial by fire" of a real (indoor) archaeological excavation, which will be the topic of one of the next posts in ATOR.

Ciao.

Kinect 3D outdoor: hacking the hardware

Some weeks ago I finally found the time to modify our Kinect in order to test it outdoor. 

My main problem was the power supply, while in an archaeological excavation it can be difficoult to find an access to electricity. The solution was obviously an external battery, but I did not know the right voltage and amperage. Finally I found this interesting post, in Ken Mankof blog, with all the necessary informations to hack Kinect for the fieldwork.

I tried to summarize all the operations I did in the image below:

The modified Kinect

As you can see, Kinect's main cable ends with an USB (for data transfer) and with an electric plug (for power supply). I cut the cable before the elctric plug and I added a connectors pair, positioning the male one on the Kinect side and the female one on the electric plug side. Then I prepared another cable with a female connector at one end and two different female blade connectors (faston) on the other end (one for the positive and one for the negative exit). The two female blade connectors are compatible with the two terminals (red/positive and black/negative) of a lead battery (12 V, 7.2 Ah).  In this way it is possible to switch Kinect form the electric net to the battery, simply plugging and unplugging the right cables.

After the hardware modification I was able to test Kinect outdoor. I will write soon a post with the results.

 

Iris van Herpen: how to make clothes with the prototyping

Recently we talked about prototyping applied to the museum context. Maybe for those who are not accustomed to such matters, this argument can seem quite difficult to understand.

In particular, it may be difficult to imagine a 3D printer that works to build dioramas. The idea of ​​diorama, in fact, remained quite frozen in the representations housed behind the windows of the natural history museums of the nineteenth century and much of the twentieth century.

These are hand-crafted dioramas, often made using materials taken from the natural environments of origin of the animals of which is meant to represent the habitat. Today, the dioramas are designed differently, meeting even the most modern artistic aspect in some successful demonstrations.

To aid people to understand, I'll give an example of prototyping completely divorced from the museal context. In fact, I will speak of the use of prototyping in fashion, illustrating the work of Iris van Herpen.

Iris van Herpen, born in Holland in 1984, became known for his clothes really special: two of her cherished customers are Lady Gaga and Björk.

After a sketch of the dress, Van Herpen drapes it on a virtual model and then entrusts the result to Materialise, a Belgian company that makes 3D prints. As she says, during this process, his tailoring is transformed into a laboratory where creation, emotion and technology fuse together to give a really particular aesthetic vision.

What impressed the fashion world, it was the perfect combination of craftsmanship knowledge and applications of new technologies. The end result is a suit that surprises for its consistency somewhere between the organic and the synthetic way. A synthetic way that seems to come from the future.

It is no coincidence that TIME Magazine has included her clothes among the 50 best innovations of 2011.

Her models are composed of different materials ranging from rubber to plastic. It's interesting the comment of the stylist about her "first time" with the prototyping:

The first time I used 3D printing, it completely changed my thinking. It freed me from all physical limitations. Suddenly, every complex structure was possible and I could create more detail than I ever could by hand.

Instead of depleting her creativity, prototyping expands it, opening new horizons. If this was possible in the field of fashion, why can't it could do in the area of ​​cultural heritage?

Extreme SfM: fast data acquisition and particular light condition

Hi all,

this post reports some technical informations regarding Cicero's article about Converting pictures into a 3D mesh with PPT, MeshLab and Blender.

The experiment to digitally document in 3D a statue of the Egyptian Museum in Torino (IT) was aimed to hardly test the potentialities of SfM techniques in archaeology. 

The idea just came when I was visiting the exposition with my wife Kathi, during an holiday: I asked the guardians if it was possible to take photos and they answerd me that there were no problems as long as I was not using the flash.

As you can see from the picture below, I found a perfect situation when I reached the first statue's room; the athmosphere was charming, while the sculptures were in darkness, with only a spot light to make them stand out. 

Spot light condition

This particular light condition was a good test for SfM techniques because I could not modify it "artificially" (e.g. with other lamps to get a better illumination of my subject). Moreover I could not use the flash, so I had to turn the ISO of my Nikon D70 to the maximum value, in order to be able to take pictures without the help of a tripod.

Another difficulty arose from the necessity to acquire the data quickly, without disturbing the visit of the other tourists.

The croweded room

Anyway, having increased the ISO of the camera, it was not a problem to collect all the data in just a couple of minutes.

Once home, I tried to do a 3D digital model with SfM and IBM techniques, using Pierre Moulon's PPT. Since I did not think to succeed in my purpose, I did just a fast 3D model, with low quality parameters (scaling all the pictures on a medium resolution). Contrary to what I thougth the model was accurate enought and the experimentation went on thanks to the collaboration of Cicero Moraes, who was able to recreate an high quality texture, using the methodology he described in his post.

The 3D low quality model in Paraview

CREDITS:

This article was possible thanks to the kindness of Dott.ssa Paola Matossi L'Orsa and Dott.ssa Sara Caramello and with the permission from the "Fondazione Museo delle Antichità Egizie di Torino".

Good ideas, new technologies and museum experiences

The digitization of finds, as we saw in a previous post, has both advantages and disadvantages from different points of view. Leaving aside problems related to the economic sphere of the possible beneficiaries of their business (in the broadest sense), it is clear, however, that the technology that concerns the digitization has legitimized their use to a wider audience.

An audience that otherwise, perhaps by choice or particular socio-cultural conditions, would not get in touch with the same finds and, in return, to the sciences that study them.

The museum exhibitions and the educational exhibits are among the main beneficiaries of this new approach. It's a fact that an exhibition like Homo sapiens, which was held recently in Rome, would not have had the same impact on visitors if it had not made use of multimedia and interactive tools of a certain importance.

It is not just to amaze the visitor, but to help him to obtain, from its interaction with the exhibition, a real experience of the visit. Without this experience, in fact, hardly the visitor will reflect deeply on what he has seen and he will not derive useful advantage to his daily life. An advantage represented by an idea to be applied in his field of work, rather than the sheer relief given by the experience of beauty / interesting aspect.

The exhibition "Homo sapiens" is an example that can be misleading if we think, in general, to the usefulness of these technologies in the museum context. An example misleading because of the large investments and of spaces that were not the common ones.

Collaborating with local museums, I often deal with problems of exposure of the findings. The scarcity of economic resources that small museums often have to deal with and that basically is inherent to the very idea of ​​a small museum (economic crisis or not) does not allow "easy" solutions that often coincide with high costs.

I recently reflected upon the relationship between technology and costs of the exhibitions, when I thought to the use of dioramas for a particular museum. The construction of models, when there is the possibility, is entrusted to specialized firms, sometimes to skilled artisans, more often to willing people who deal with it as a hobby and have a certain skill.

In this process, the technology is almost zero: the digitization and prototyping of models do not seem to be one of the basic tools to simplify the work of mounting. However, their potential is evident and the costs are relatively affordable, although it is to recognize that there is an objective problem of dissemination of this knowledge, which seem yet cabalistic material for the initiated few.

Build a diorama using rapid prototyping allows a considerable saving of time and costs, in addition to providing the basic material for the merchandising of a museum. If there is indeed a product segment that captures the imagination of the visitor is the object able to represent the visit just completed and that reminds him of the physical place where the visit took place (I omit here the anthropology of souvenirs which plays, however, its important part in this (re)cognition).

It's true that this process happens if the visit becomes experience and, therefore, as mentioned above, the visitor feels that he has acquired / purchased something applicable in other contexts. Therefore it's necessary, beyond the technological tools to be used, not forget that the visitor is at the center of everything, and that the finds in itself is only a means to educate him. “Education”, here, is not only the assimilation of information, but the opening of a new feeling about the topics covered.

So, without a good idea, the technology amazes without creating surprising experience, but without technology a good idea turns into a sterile list of information on a wall panel.

The link between idea and technology is in the experimental use (again, experience is the main part of the learning process and application) of the tools available, in a feedback process that goes from the idea to technology and vice versa. That is what has been experienced by our hominid ancestors with the feedback circuit formed by hand and brain, which created the language and has allowed both the biological and cultural evolution.

And the exhibits, in a certain way, are nothing more than a continuation of this process.

Converting pictures into a 3D mesh with PPT, MeshLab and Blender

Obs.: Please, read the article http://arc-team-open-research.blogspot.com.br/2012/09/extreme-sfm-fast-data-acquisition-and.html with technical information that is important and complementary about the technique, place and manner that the photographs were taken.

SfM is a powerful technology that allow us convert a picture sequence in a points cloud.

MeshLab is a usefull software in 3D scanning tool, that is in constant development and can be used to reconstruct a points cloud in a 3D mesh.

Blender is a most popular opensource software of modeling and animation , with a intuitive UV mapping process.

When we joint the three software they allow us create a complete solution of picture scanning.

The process will be described superficially for that already have a few knowledge about the tools used to do this reconstruction.

First of all, was needed a group of pictures that was converted in a points cloud with Python Photogrammetry Tools.

The picture was taken without flash. This make the process harder in the future, when is needed use the image how reference to create the relief of the surface.

MeshLab was used to convert the points cloud into a 3D mesh with Poison reconstruction.

The surface was painted with vertex color.

The 3d mesh and the points cloud was imported in Blender.

The points cloud was imported because it have the information about the cameras point (orange points).

Using this points was possible placed the camera in the right position.

The vanishing points was matched using the focla distance of the camera. But, how we can see in the image above the mesh didnt match with the reference picture.

To point the camera was needed to orbit it manually.

Blender have a good group of UV Mapping tools. It is possible to use only the interest region of the picture to make a final texture map, how we can see in the infographic above.

So, in this process each viewpoint texture was projected using a picture. Above we can see in right the original image, and in the left the mesh with the projected texture. This appears to be perfect because the viewpoint of the camera is the same viewpoint of the picture.

But, if the 3D scene is orbited, we can attest that the projection works well only in the last viewpoint.

So, a good way to make the final texture is using the viewpoint of the picture to paint only the interest area.

When the scene is orbited we can attest that only the interest area was painted.

The surface have to be painted using some viewpoints, to complete bit by bit the entire texture.

We can see the finished process above. It isn't needed using all pictures taken to build the final texture. Depending on complexity of the model inly four images will be needed to complete the entire texture.

Now we can compare the texture process and the vertex paint process. In this case the texture process was more interesting to be used.

The resulted mesh have a hight level of details and nevertheless can be used to be viewed in realtime (see the video in the top).

To increase the mesh quality, we can use the Displacement Modifier in Blender. It project the relief of the surface using the texture how reference.
The final result:

CREDITS:

This article was possible thanks to the kindness of Dott.ssa Paola Matossi L'Orsa and Dott.ssa Sara Caramello and with the permission from the "Fondazione Museo delle Antichità Egizie di Torino".

Young anthropologists meeting in Florence

Hi all,
just a fast post to advice that tomorrow will start the firts italian meeting of the "Young anthrologists" in Florence (September 13-14, 2012). The event is under the patronage of the AAI (Associazione Antropologica Italiana) and of the ISItA (Istituto Italiano di Antropologia); it will take place in the Anthropology Laboratories of the Department of Evolutionary Biology "Leo Pardi" (Florence University). Here is the official program of the conference. We (Arc-Team) will partecipate with a contribution of Cicero Moraes, Giuseppe Naponiello and Silvia Rezza ("A sperimental methodology of craniofacial digital reconstruction with FLOSS")  and during the final discussion about "Open Source e Open Data in italian anthropology and archaeology", with a presentation of Alessandro Bezzi and Luca Bezzi ("Anthropology and Open Source, the experience of Arc-Team".

The official logo