{"id":348,"date":"2019-09-02T21:47:57","date_gmt":"2019-09-02T21:47:57","guid":{"rendered":"http:\/\/alexandrix.com\/blog\/?p=348"},"modified":"2019-09-06T21:43:47","modified_gmt":"2019-09-06T21:43:47","slug":"a-live-virtual-world-creation","status":"publish","type":"post","link":"https:\/\/alexandrix.com\/blog\/a-live-virtual-world-creation\/","title":{"rendered":"A live virtual world creation"},"content":{"rendered":"\n<p>From August 26th to 29th, 2019 I was invited to take part in the GRETSI 2019 symposium on signal processing (<a rel=\"noreferrer noopener\" aria-label=\"link (opens in a new tab)\" href=\"http:\/\/gretsi.fr\/colloque2019\/\" target=\"_blank\">link<\/a>, FR).<\/p>\n\n\n\n<p>My role there was specific: creating a whole new virtual world inspired by the <strong>essence of GRETSI<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-embed-vimeo wp-block-embed is-type-video is-provider-vimeo wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" src=\"https:\/\/player.vimeo.com\/video\/357425722?dnt=1&amp;app_id=122963\" width=\"640\" height=\"360\" frameborder=\"0\" allow=\"autoplay; fullscreen\" allowfullscreen title=\"GRETSI VR 2019 - Film (FullHD)\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">The concept<\/h2>\n\n\n\n<p>We can picture the initiative as a sort of <strong>happening<\/strong>. Set up on an amphitheater stage with a laptop and a VR headset, I would start building an empty world. Throughout the creation process, the screen would be mirrored on a wide projection screen behind me, so people could witness the <strong>making of<\/strong> the world. The VR headset was plugged in, so anyone could be <strong>immersed right inside the world I was creating live<\/strong> around them.<\/p>\n\n\n\n<p>Occasionally, I would stop working on it and welcome any discussions, about my presence, GRETSI overall, and particularly about what the person in front of me was working on as a researcher or engineer.<\/p>\n\n\n\n<p>At times, an explanation or a specific thought on a topic would spark an idea that I could explore further to create a virtual object.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The outcome<\/h2>\n\n\n\n<p>Using <strong>particles and force field equations<\/strong> in three dimensions to depict bits of an imaginary world, 4 objects were born.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Axons<\/h3>\n\n\n\n<p>As all objects except the last one, this object is inspired by a discussion with a researcher. I came to realize that in our brain, some neurons have a much more important role than others. Those <strong>major neurons<\/strong> can either <em>inhibit <\/em>or <em>enhance<\/em> information transmission.<\/p>\n\n\n\n<p>3 of these major neurons are represented at the center of the object. Particles spawn on the surface of concentric spheres with oscillating radii. We can think of it as either the <strong>propagation of information<\/strong>, or its destruction. The chosen colors and turbulent shape can be thought of as a metaphor of the <strong>brain<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_1090-1024x576.png\" alt=\"\" class=\"wp-image-353\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_1090-1024x576.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_1090-300x169.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_1090-768x432.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_1090.png 1920w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>On a technical level, 3 spring attractors drag particles closer to neurons. The surrounding turbulence is a 3D Perlin noise. Some viscosity is added to calm things down a bit.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Stegano<\/h3>\n\n\n\n<p>This pattern is inspired by the concept of <strong>steganography<\/strong>. Steganography is a set of techniques used to <strong>conceal information<\/strong> within another source of information, such as sound or image. It instantly reminded me of the <strong>anamorphosis<\/strong> techniques: when the image you form of an object strongly depends on the point of view.<\/p>\n\n\n\n<p>So it started with an idea of building a particle cloud, that from a precise view location looked triangular and from aside looked square-shaped. Deriving from this initial idea, I laid a series of vertical squares with increasing size, thus forming a square cone that just looked like a single square from the right angle. Shifting to a different size pattern and then stretching the planes vertically, the final object can be viewed as <strong>a door to a new dimension<\/strong> of hidden information.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_2027-1024x576.png\" alt=\"\" class=\"wp-image-354\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_2027-1024x576.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_2027-300x169.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_2027-768x432.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_2027.png 1920w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Note: Unexpectedly, PhD student <em>Ve\u00efs Oudjail<\/em> and then several other signal processing researchers pointed out that the object fitted well with the representation of the <strong>encoding and decoding in artificial neural networks<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Dimension 1 000 000<\/h3>\n\n\n\n<p>A researcher made me realize that a <strong>1 Mpx image<\/strong> can be viewed as a 1-million-dimensional vector space. This was the origin of a new goal: representing a flat grid of squares, with 3 or 4 vectors originating from each square (RGB or RGBA).<\/p>\n\n\n\n<p>For some reason, I ended up depicting the <strong>HSL color space<\/strong> instead. HSL (or HSV) is a cylindrical color space, with Saturation and Lightness as 2 linear dimensions and Hue as the color angle. Slices of the HSV space are depicted, with their <strong>gradients in saturation and lightness<\/strong>, as well as garish <strong>edge-less cubes<\/strong>. The rawness of the colors is a <strong>tribute to the RGB color space<\/strong> from the HSL color space, because RGB has been the way color is encoded in our hardware since more than half a century, while HSL is &#8216;merely&#8217; a very handy layer on top of RGB.<\/p>\n\n\n\n<p>From certain angles, cubes look like flat hexagons, creating a confusion on the nature of color information.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3490-1024x576.png\" alt=\"\" class=\"wp-image-355\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3490-1024x576.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3490-300x169.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3490-768x432.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3490.png 1920w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Particles don&#8217;t have a motion, but spawn and die very quickly. This, together with the fact that their position depends on their instantiation index that rotates over time, contributes to a <strong>glitchee old-fashioned vision of information technology<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Gretsahedron<\/h3>\n\n\n\n<p>The final object in the GRETSI VR scene is a sort of sphere that changes shape depending on your distance from it. It was born from looking at the <strong>GRETSI logo<\/strong>: almost 3 perfect circle arcs. What if you expand those arcs into circles, positioned on the vertices of a triangle? What if you add a third dimension, and position <strong>spheres on the vertices of a regular tetrahedron<\/strong>?<\/p>\n\n\n\n<p>With some gentle turbulence and special force fields that conform the particle clouds into spheres of varying radii, what we see is <strong>the intersection<\/strong> of those spheres. Playing with the tetrahedron size creates different patterns. From afar, you can notice the shape of the GRETSI logo.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3920-1024x576.png\" alt=\"\" class=\"wp-image-356\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3920-1024x576.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3920-300x169.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3920-768x432.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_3920.png 1920w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>From closer, it slowly transforms into something rounder.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4350-1024x576.png\" alt=\"\" class=\"wp-image-357\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4350-1024x576.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4350-300x169.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4350-768x432.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4350.png 1920w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>When you reach the inside of it, it becomes perfectly spherical: <em>you entered the world of GRETSI<\/em>.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4570-1024x576.png\" alt=\"\" class=\"wp-image-358\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4570-1024x576.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4570-300x169.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4570-768x432.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_4570.png 1920w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Acknowledgements<\/h2>\n\n\n\n<p>GRETSI organization committee<br>Patrice Abry<br>Pierre Chanais<br>Ludovic Macaire<br>Th\u00e9o Taburet<br>Ve\u00efs Oudjail<br>Guillaume Becq<br>Laurent Duval<br>Antoine Mazarguil <br>Leah &amp; Jeff Vuolo<\/p>\n\n\n\n<p>&amp; all GRETSI folks who shared the experience<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_5163-1024x576.png\" alt=\"\" class=\"wp-image-359\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_5163-1024x576.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_5163-300x169.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_5163-768x432.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/09\/image_5163.png 1920w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Full video extract directly on Vimeo: <a rel=\"noreferrer noopener\" aria-label=\"GRETSI VR 2019 - Film (FullHD) (opens in a new tab)\" href=\"https:\/\/vimeo.com\/357425722\" target=\"_blank\">GRETSI VR 2019 &#8211; Film (FullHD)<\/a><\/p>\n\n\n\n<p><br><\/p>\n","protected":false},"excerpt":{"rendered":"<p>From August 26th to 29th, 2019 I was invited to take part of the GRETSI 2019 symposium on signal processing. My role there was specific&#8230;<\/p>\n","protected":false},"author":1,"featured_media":359,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"_links":{"self":[{"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/posts\/348"}],"collection":[{"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/comments?post=348"}],"version-history":[{"count":13,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/posts\/348\/revisions"}],"predecessor-version":[{"id":370,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/posts\/348\/revisions\/370"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/media\/359"}],"wp:attachment":[{"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/media?parent=348"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/categories?post=348"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/tags?post=348"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}