{"id":372,"date":"2019-12-09T18:36:19","date_gmt":"2019-12-09T18:36:19","guid":{"rendered":"http:\/\/alexandrix.com\/blog\/?p=372"},"modified":"2020-02-20T11:48:19","modified_gmt":"2020-02-20T11:48:19","slug":"portraits-n2","status":"publish","type":"post","link":"https:\/\/alexandrix.com\/blog\/portraits-n2\/","title":{"rendered":"Portraits, n\u00b02"},"content":{"rendered":"\n<p><strong><em>Portraits<\/em><\/strong> is a format of collaboration where I <em>immerse myself in the world and the work of a scientist to create a painting<\/em>.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-724x1024.jpg\" alt=\"\" class=\"wp-image-409\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-724x1024.jpg 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-212x300.jpg 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-768x1086.jpg 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10.jpg 894w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><figcaption><em>Portraits, n\u00b02 &#8211; <\/em><strong><em>Vacherie Ternaire<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n<p>The second <em>Portraits<\/em> project has something peculiar: it was orchestrated as a present for the researcher, who was not aware until the very end that our interactions would lead to a printed artwork. We met for a very short time: <em>2 hours<\/em>. It was thus a challenge to <strong>gather enough insight to drive a new creation<\/strong>. Hopefully, I had a few extra resources I could analyze later on my own: publications, videos and lectures.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">About the work of Alain Pumir<\/h2>\n\n\n\n<p><em>Alain<\/em>&#8216;s research encompasses a variety of topics around <strong>turbulence<\/strong>. For instance, he investigates the way ice crystals form in <strong>clouds<\/strong> and how they collide with surrounding droplets &#8211; so, liquid phase &#8211; to capture them. This process is called <strong>riming<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"747\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Riming-slide-Pumir-1024x747.png\" alt=\"\" class=\"wp-image-373\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Riming-slide-Pumir-1024x747.png 1024w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Riming-slide-Pumir-300x219.png 300w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Riming-slide-Pumir-768x560.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Riming-slide-Pumir.png 1350w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption>A slide from one of Alain&#8217;s lectures about the riming process <\/figcaption><\/figure>\n\n\n\n<p>Studying motion under those conditions is tricky, as unlike other turbulence experiments that already have their share of complexity and where you just look at a particle&#8217;s position, you now need to analyze <strong>crystal orientation<\/strong>, <strong>mass<\/strong> increase, <strong>size<\/strong> variation, shape, etc.<\/p>\n\n\n\n<p>Alain also looks at <strong>how vortices merge<\/strong>. But first, you actually need to create the conditions to observe vortices! An experiment was set up for this purpose:<\/p>\n\n\n\n<figure class=\"wp-block-video\"><video controls src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Video-Alains-work-vortex-merging.mp4\"><\/video><figcaption> Credits: R. McKeown, R. Ostilla-M\u00f3nico, A. Pumir, M. P. Brenner, S. M.  Rubinstein &#8211; Harvard University, University of Houston, Laboratoire de  Physique ENS de Lyon, SMR Lab<br>Full video and more information on <a rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\" href=\"https:\/\/gfm.aps.org\/meetings\/dfd-2018\/5b9ad86eb8ac3105e5ac8e1e\" target=\"_blank\">https:\/\/gfm.aps.org\/meetings\/dfd-2018\/5b9ad86eb8ac3105e5ac8e1e<\/a><\/figcaption><\/figure>\n\n\n\n<p>Close analysis revealed <strong>vortex filaments with varying intensity and orientation<\/strong>. Three categories were proposed: primary filaments, secondary filaments and tertiary filaments. We can imagine the cascade to go further but at those scales the fluid is so chaotic we might not be able to do that.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Starting on 2D turbulent flows<\/h2>\n\n\n\n<p>Inspired by the <a rel=\"noreferrer noopener\" aria-label=\"https:\/\/earth.nullschool.net\/ (opens in a new tab)\" href=\"https:\/\/earth.nullschool.net\/\" target=\"_blank\">https:\/\/earth.nullschool.net\/<\/a> visualization of water current and wind flows on Earth, I started with <strong>a simple vortex<\/strong>.<\/p>\n\n\n\n<p>The mathematical description we can choose for a vortex is a velocity field made of two components: an orthoradial component that controls the particle <strong>rotation speed based on its distance to the vortex center<\/strong>, and a radial law that slightly attracts particles to the center.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"865\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-early-step-1-865x1024.jpg\" alt=\"\" class=\"wp-image-378\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-early-step-1-865x1024.jpg 865w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-early-step-1-253x300.jpg 253w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-early-step-1-768x910.jpg 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-early-step-1.jpg 993w\" sizes=\"(max-width: 865px) 100vw, 865px\" \/><figcaption>Earliest creation step with simple inwards flow<\/figcaption><\/figure>\n\n\n\n<p>Code-wise, the vortex\/eddy can become an object with a reduced number of parameters:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let eddy = { x0: 100, y0: 250, K: 10, r0: 20 }<\/code><\/pre>\n\n\n\n<p>Where <em>(x0, y0)<\/em> is the vortex center, <em>K<\/em> is the main intensity and <em>r0<\/em> a base radius for which rotation speed is maximal.<\/p>\n\n\n\n<p>And for instance the orthoradial component can be written as a simple Gaussian function.<\/p>\n\n\n<span class=\"wp-katex-eq\" data-display=\"false\"> azimuthalVelocity = K \\cdot e^{- ({ \\frac{r(x_0, y_0) - r_0}{sigma} })^2 } <\/span>\n\n\n\n<p> <br>Now you can just <strong>take several eddies and add them up<\/strong> to form turbulent flows. Eddies of same intensity sign will add up to create wider eddies, while neighboring eddies with opposite signs will create transition zones.<\/p>\n\n\n<p class='codepen'  data-height='500' data-theme-id='1' data-slug-hash='rNaxdLP' data-default-tab='result' data-animations='run' data-editable='' data-embed-version='2'>\n\nSee the Pen A world of Turbulence \u2013 One big vortex by Alex Andrix on CodePen\n<\/p>\n\n\n\n\n<p style=\"color:#555555;text-align:center\" class=\"has-text-color\">Sum of four eddies with same sign intensity (+ + + +)<\/p>\n\n\n\n<p>  K and r0 also have different values so the flows are a bit asymmetric.<\/p>\n\n\n<p class='codepen'  data-height='500' data-theme-id='1' data-slug-hash='mdyVxqm' data-default-tab='result' data-animations='run' data-editable='' data-embed-version='2'>\n\nSee the Pen A world of Turbulence \u2013 Vortex transitions by Alex Andrix on CodePen\n<\/p>\n\n\n\n\n<p style=\"color:#555555;text-align:center\" class=\"has-text-color\"> Sum of four eddies with opposite sign intensities (- + &#8211; +)<\/p>\n\n\n\n<p> <br>Video below captures a few creation steps that were presented this <em>summer<\/em>.<\/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\" title=\"Extract aper&amp;ccedil;univers - S&amp;eacute;minaire Pop&#039;Sciences 11\/07\/2019\" src=\"https:\/\/player.vimeo.com\/video\/347362448?h=de45dbd43c&amp;dnt=1&amp;app_id=122963\" width=\"640\" height=\"360\" frameborder=\"0\" allow=\"autoplay; fullscreen; picture-in-picture\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Going 3D<\/h2>\n\n\n\n<p>While going through those steps, I came to believe that using vortices in 3D would be a better tribute to the complexity of Alain&#8217;s work. It could also lead to potentially richer artworks with <strong>depth information<\/strong>.<\/p>\n\n\n\n<p>After a few cross products to define local <strong>cylindrical coordinate systems<\/strong> and a law to paint closer trajectory segments larger:<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-first-3d-step-724x1024.jpg\" alt=\"\" class=\"wp-image-387\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-first-3d-step-724x1024.jpg 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-first-3d-step-212x300.jpg 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-first-3d-step-768x1086.jpg 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-portraits-2-first-3d-step.jpg 993w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><figcaption>One single vortex with depth. Slight linear increase of base radius along axis.<\/figcaption><\/figure>\n\n\n\n<p>Looking at the code, eddies now carry information of <strong>axis orientation<\/strong>.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>this.eddies.push({\n     origin: { x: 0, y: -700, z: 0 },\n     axis: { x: 1, y: 0, z: -0.7 },\n     K: -10,\n     r0: 200\n })<\/code><\/pre>\n\n\n\n<p>At that point I knew that I wanted to depict the merge of <strong>3 vortices with different orientations<\/strong>. Each would form a 90\u00b0 angle with each other, just like successive generations of filaments perhaps? Also, my only instruction was to paint <strong>black&amp;white<\/strong>.<\/p>\n\n\n\n<ul class=\"wp-block-gallery columns-3 is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\"><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562598272201-724x1024.png\" alt=\"\" data-id=\"389\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=389\" class=\"wp-image-389\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562598272201-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562598272201-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562598272201-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562598272201.png 993w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599230669-724x1024.png\" alt=\"\" data-id=\"390\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=390\" class=\"wp-image-390\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599230669-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599230669-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599230669-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599230669.png 993w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599641815-724x1024.png\" alt=\"\" data-id=\"391\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=391\" class=\"wp-image-391\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599641815-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599641815-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599641815-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562599641815.png 993w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601273898-724x1024.png\" alt=\"\" data-id=\"392\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=392\" class=\"wp-image-392\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601273898-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601273898-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601273898-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601273898.png 993w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601500096-724x1024.png\" alt=\"\" data-id=\"393\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=393\" class=\"wp-image-393\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601500096-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601500096-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601500096-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562601500096.png 993w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562602200023-724x1024.png\" alt=\"\" data-id=\"394\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=394\" class=\"wp-image-394\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562602200023-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562602200023-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562602200023-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-993-1404-1562602200023.png 993w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><\/ul>\n\n\n\n<p>27 iterations later, some of which are presented above, I came up with that final result.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Petite-Vacherie-724x1024.png\" alt=\"\" class=\"wp-image-396\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Petite-Vacherie-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Petite-Vacherie-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Petite-Vacherie-768x1086.png 768w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><figcaption>Petite Vacherie<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Hold on<\/h2>\n\n\n\n<p>Actually the next day I canceled my submission to the printer and worked on <strong>a few more iterations<\/strong>, willing to get more impact and more of that 2D flow feeling for the middle eddies.<\/p>\n\n\n\n<ul class=\"wp-block-gallery columns-3 is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\"><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670234346-724x1024.png\" alt=\"\" data-id=\"397\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=397\" class=\"wp-image-397\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670234346-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670234346-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670234346-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670234346.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670696755-724x1024.png\" alt=\"\" data-id=\"398\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=398\" class=\"wp-image-398\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670696755-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670696755-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670696755-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562670696755.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562671182402-724x1024.png\" alt=\"\" data-id=\"399\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=399\" class=\"wp-image-399\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562671182402-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562671182402-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562671182402-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562671182402.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562672643855-724x1024.png\" alt=\"\" data-id=\"400\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=400\" class=\"wp-image-400\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562672643855-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562672643855-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562672643855-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562672643855.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673192046-724x1024.png\" alt=\"\" data-id=\"401\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=401\" class=\"wp-image-401\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673192046-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673192046-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673192046-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673192046.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673389285-724x1024.png\" alt=\"\" data-id=\"402\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=402\" class=\"wp-image-402\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673389285-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673389285-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673389285-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562673389285.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562674062887-724x1024.png\" alt=\"\" data-id=\"403\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=403\" class=\"wp-image-403\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562674062887-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562674062887-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562674062887-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562674062887.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562675275178-724x1024.png\" alt=\"\" data-id=\"404\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=404\" class=\"wp-image-404\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562675275178-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562675275178-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562675275178-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562675275178.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676180873-724x1024.png\" alt=\"\" data-id=\"405\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=405\" class=\"wp-image-405\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676180873-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676180873-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676180873-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676180873.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676381940-724x1024.png\" alt=\"\" data-id=\"406\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=406\" class=\"wp-image-406\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676381940-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676381940-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676381940-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562676381940.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562677807177-724x1024.png\" alt=\"\" data-id=\"407\" data-link=\"https:\/\/alexandrix.com\/blog\/?attachment_id=407\" class=\"wp-image-407\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562677807177-724x1024.png 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562677807177-212x300.png 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562677807177-768x1086.png 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/artwork-1986-2808-1562677807177.png 1986w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/figure><\/li><\/ul>\n\n\n\n<p>Instead of allowing all <strong>grey levels<\/strong> between 0 and 1, I opted for a set of chosen values for particle trails. In the HSL color space with a <strong>saturation of 0%<\/strong>, luminosity would be randomly chosen in the array <strong>[10, 25, 35, 50, 70, 95]<\/strong>. The upper vortex axis was also tilted towards the viewer.<\/p>\n\n\n\n<p>Finally, <em>Vacherie Ternaire<\/em>.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"724\" height=\"1024\" src=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-724x1024.jpg\" alt=\"\" class=\"wp-image-409\" srcset=\"https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-724x1024.jpg 724w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-212x300.jpg 212w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10-768x1086.jpg 768w, https:\/\/alexandrix.com\/blog\/wp-content\/uploads\/2019\/12\/Vacherie-ternaire-10.jpg 894w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><figcaption><em>Vacherie Ternaire<\/em><\/figcaption><\/figure>\n\n\n\n<p>The painting was offered to Alain during 2019&#8217;s <em>Crossed Pathways in Turbulence<\/em> conference.<\/p>\n\n\n\n<p>Thanks for reading!<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Acknowledgements<\/h2>\n\n\n\n<p><em>Alain Pumir<\/em><br><em>X-Pathways in Turbulence organizing committee<\/em><br><em>Researchers @ Laboratoire de Physique ENS de Lyon \/ friends<\/em> <br><em>Vuolo team<\/em><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Links<\/h2>\n\n\n\n<p><a href=\"http:\/\/www.ens-lyon.fr\/PHYSIQUE\/presentation\/annuaire\/pumir-alain\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\">Alain Pumir<\/a><br><a rel=\"noreferrer noopener\" aria-label=\"Alex Andrix (opens in a new tab)\" href=\"https:\/\/alexandrix.com\" target=\"_blank\">Alex Andrix<\/a><br><a rel=\"noreferrer noopener\" aria-label=\"Laboratoire de Physique ENS de Lyon (opens in a new tab)\" href=\"http:\/\/www.ens-lyon.fr\/PHYSIQUE\/\" target=\"_blank\">Laboratoire de Physique ENS de Lyon<\/a><br><a rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\" href=\"http:\/\/www.ens-lyon.fr\/en\/event\/research\/crossed-pathways-turbulence\" target=\"_blank\">Crossed Pathways in Turbulence<\/a> conference<br>More about <a rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\" href=\"https:\/\/alexandrix.com\/blog\/portraits\/\" target=\"_blank\">Portraits<\/a><\/p>\n\n\n\n<p>  <br>Bonus: <strong>random turbulent flow generator<\/strong><\/p>\n\n\n<p class='codepen'  data-height='500' data-theme-id='1' data-slug-hash='jgyWww' data-default-tab='result' data-animations='run' data-editable='' data-embed-version='2'>\n\nSee the Pen A random world of Turbulence by Alex Andrix on CodePen\n<\/p>\n\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The second Portraits project was orchestrated as a present for the researcher. 2 hours of interaction and 112 iterations for a new creation.<\/p>\n","protected":false},"author":1,"featured_media":409,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"_links":{"self":[{"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/posts\/372"}],"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=372"}],"version-history":[{"count":32,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/posts\/372\/revisions"}],"predecessor-version":[{"id":451,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/posts\/372\/revisions\/451"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/media\/409"}],"wp:attachment":[{"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/media?parent=372"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/categories?post=372"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/alexandrix.com\/blog\/wp-json\/wp\/v2\/tags?post=372"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}