Tuesday, May 08, 2007

Great Time and Science in Erice

Between the 15th and 22nd April, I was at the 6th International Workshop on Data Analysis in Astronomy «Livio Scarsi». The workshop was organized in Erice at the Ettore Majorana Foundation and Centre for Scientific Culture. The conference theme was quite large, Modelling and Simulation in Science, with contribution from three major branches: Astrophysics, Biology and Climatology. With my PhD Student, J.C. Torrel, we presented our works on hierarchical muti-agent approach through two examples: LifeDrop for the study of evolution dynamics and our results in comological simulations. A great time with many interactions, in a delightful medieval ambience and splendid location of Erice located on high ground overlooking the northern coast of western Sicily.

Tuesday, May 01, 2007

New 3D Biomorphs for LifeDrop

Finally, we have choosen a new 3D design approach for the LifeDrop virtual creatures. Each biomorph is composed of a set of 3D building blocks: segments, head, tail, antenna, eyes, etc. The DNA of a creature includes a structural template thatcan be evolved through mutation, cross-over and natural selection. The set of possible creatures is very big even if not really infinite. As in the previous version of LifeDrop, there are three basic types of creatures: (1) predators haunting any other creatures, and (2) preys eating (3) weeds in the virtual water drop. The software is under development in Java and a realtime 3D engine that will enable to render biomorphs with a higher level of realism compared to the previous versions that were quite minimalistic from this point of view (see preview images). The 3D engine will manage two models for each creature: a "low-polygons" model for the rendering of the ecosystem as a whole, and a "high-polygons" model in a dedicated "magnifying glass" window.
Another goal of this new implementation is to reduce the number of parameters for experiments. This is important in order to have a more precise study of evolution dynamics. With two many parameters, it is quite difficult to analyze which ones are really meaningfull and those which are useless and only add noise in experiments. LifeDrop version 4 is now an on-going project...

Sunday, April 22, 2007

Holographic Globular Cluster

The third installation of our exhibition was based on our research about 3D Gravitational agents. The idea was to show some results of our simulations in 3D. We used two big LCD screens to display an introduction on emergent patterns at differents scales in the universe and the evolution of a globular cluster from a random distribution of matter. Pascal Gauchet of the Holographic Lab. in Paris has given us the opportunity to use an holographic station for experiments. The image shows the resulting installation where the user can see an hologram of a globular cluster turning around just in front of his eyes.
Then, with one hand, the user was able to virtually "grap" the hologram and select the image he wanted to see on the left screen by turning the hologram in the desired direction. This sort of "holographic mouse" used a webcam and a simple image processing program to detect the hand movement. It worked quite well when well calibrated. The main prolem with this webcam solution is that a small change in light condition can affect the quality of the resulting behavior. I think that an infrared grid could be a more robust solution...

Wednesday, March 28, 2007

Eva Virtual Creature Meets the Real World

This is an image of the second EVA installation we have made for the exhibition. This installation is based on the Evolutionary Virtual Agent technology for its Artificial Intelligence part. It basically enables the creature to interact with the user in natural language. In the near future, Eva will be also able to learn about the user and to search information on the web.

The 3D interface was designed by a team of students (see previous posts on thatsubject). Animations like eyes blinks or emotional expressions are realized by simply switching images. A java Applet is responsible for displaying in real-time the face. The talking head is then projected on a physical form, that is a 3D sculpture representing thetop of the body and the face. This 3D model has been simplified and virtually tested to enable most facial animations without image distortion (see image on the right). It is interesting to note that the resulting model may recall some sort of paleolithic venus figurines or ancient egyptian scluptures. Anayway, the resulting effect is amazing. The projection on a physical model gives "life" to the artificial creature. Eva becomes real.

Saturday, March 24, 2007

EVA Holographic Ghost

It has been a long time since my last post. We have worked a lot on a multimedia exhibition which takes place at the Leonard de Vinci University until the end of March (www.iim.fr/expo). In the next few posts, I will describe some of the installations we have designed with our students. The first one is an holographic artificial creature based on the EVA design (Evolutionary Virtual Agent). Imagine some sort of woman ghost floating in the air just in front of you. She is dancing slowly in the air. This installation uses a simple but efficient system composed of turning cords and holographic paper. The result is amazing as you can see on the image considering the simplicity of this installation.

This installation has been designed by the french artist Cyril Vachez (http://www.holorapt.com/). This system recalls a number of simple optical devices that were invented in the nineteenth century like the ZooTrope created by William Horner in 1833. The lower picture has been taken at high speed to be able to see the principle of this system. It is mainly composed of two parts. The first part includes a set of holographic cords, an electric engine with a speed variator, and a roller skate wheel fixed on the ceiling. The second part includes a PC computer running the artificial creature movie or program, and a video projector. This "holographic ghost" is used to introduce EVA to the visitor, just before entering the second room where he is able to interact with her. I will describe this other installation in the next post.