{"id":309,"date":"2023-11-04T18:58:42","date_gmt":"2023-11-04T18:58:42","guid":{"rendered":"https:\/\/sparkonelabs.com\/home\/?p=309"},"modified":"2023-11-17T16:22:35","modified_gmt":"2023-11-17T16:22:35","slug":"constructing-a-virtual-robot-webgl-experiment","status":"publish","type":"post","link":"https:\/\/sparkonelabs.com\/home\/2023\/11\/04\/constructing-a-virtual-robot-webgl-experiment\/","title":{"rendered":"Constructing a Virtual Robot Three.js\/WebGL"},"content":{"rendered":"\n

This post is about constructing a virtual robot WebGL experiment, using Threejs.org\/examples<\/a> as a starting point. The ultimate goal is to have a training robot similar to the ones used in automotive manufacturing. Note<\/strong> that, in this article I am trying out a bibliographical style where in post references are marked with a bracketed number, e.g. [1<\/strong>]; and the source is listed after a separator at the end of the post.<\/p>\n\n\n\n

Given References:<\/p>\n\n\n\n

    \n
  1. https:\/\/threejs.org\/examples\/#webgl_loader_collada_kinematics<\/a><\/li>\n\n\n\n
  2. https:\/\/github.com\/rdiankov\/collada_robots<\/a><\/li>\n\n\n\n
  3. http:\/\/openrave.org\/docs\/latest_stable\/robots_overview\/<\/a><\/li>\n<\/ol>\n\n\n\n

    The github project listed above had been cloned into:<\/p>\n\n\n\n

    \/home\/sparkone\/projects\/robotics\/collada_robots<\/pre>\n\n\n\n
    The collada_robots project cloned from github is a folder full of .zae files. (A .ZAE file<\/em> is a Compressed COLLADA Digital Asset Exchange file [1<\/strong>]). Well it needs to be uncompressed using zip, after renaming .zae to .zip; placed in their own directory to avoid overwriting manifest.xml. This has been accomplished and now each uncompressed .dae file exists in its own folder.<\/p>\n\n\n\n
    Well then, what is COLLADA? COLLADA is an XML-based schema that enables you to transfer data among 3D digital content creation tools, such as SketchUp, Maya, 3ds Max, and Rhino [2<\/strong>].<\/p>\n\n\n\n
    Thus the project contains robot models only. Fortunately, we have an example related to this from the old WebGL book worked from on the old site.<\/p>\n\n\n\n
    The old project website book link is down, but the URL is: http:\/\/vorticieflux6626.ihostfull.com\/oreilly\/oreilly.php<\/a>.<\/p>\n\n\n\n
    Went ahead and cloned all of https:\/\/github.com\/mrdoob\/three.js.git<\/a> into:<\/p>\n\n\n\n
    \/home\/sparkone\/projects\/robotics\/three.js<\/pre>\n\n\n\n
    This includes the documents and examples, the particular one of interest is webgl_loader_collada_kinematics<\/a>.<\/p>\n\n\n\n
    So the example needs to be isolated and analyzed, then ported onto hostgator’s server and linked.<\/p>\n\n\n\n
    Meanwhile, the openrave<\/a> project seems promising for one of the ultimate goals of this particular project. To that end the following link is noted:<\/p>\n\n\n\n
    https:\/\/www.osrobotics.org\/osr\/installation\/motion_planning.html<\/a><\/p>\n\n\n\n
    Apparently the software is intended to be installed on Ubuntu, however; it may be possible to install it on Arch Linux.<\/p>\n\n\n\n
    “Using dpkg<\/code> for this is a BadIdea\u2122. The only sensible solution is to write a PKGBUILD (if one doesn’t already exist in the AUR) which extracts the contents of the deb and repackages them correctly for Arch.<\/em>“<\/p>\n\n\n\n
    \u2013 HalosGhost<\/a>Jan 15, 2015 at 13:51<\/a>” – [3<\/strong>]. How are .deb packages compressed differently than they way they are in PKGBUILD?<\/p>\n\n\n\n
      \n
    1.  https:\/\/bbs.archlinux.org\/viewtopic.php?id=244018<\/a>. <\/li>\n\n\n\n
    2. https:\/\/cubethethird.wordpress.com\/2017\/08\/12\/installing-debianubuntu-packages-on-arch-linux\/<\/a><\/li>\n<\/ol>\n\n\n\n
      In order to rotate an arbitrary object using a 3d rotation matrix and vectors, the following post suggests that the object be translated to the origin, rotated then translated back.<\/p>\n\n\n\n
      https:\/\/math.stackexchange.com\/questions\/2093314\/rotation-matrix-of-rotation-around-a-point-other-than-the-origin<\/a><\/a><\/p>\n\n\n\n
      “Your first formula is correct. Remember, the point to which this is applied appears on the RIGHT:<\/em><\/p>\n\n\n\n
      T(x,y)\u2217R\u2217T(\u2212x,\u2212y)(P)<\/em><\/p>\n\n\n\n
      So to evaluate the expression above, we first translate P by (\u2212x,\u2212y), then rotate the result, then translate back. Let’s see what happens when P is the point (x,y,1). That amounts to evaluating the following product:<\/em><\/p>\n\n\n\n
      f((x,y))=<mtable><mtr><mtd>1<\/mtd><mtd>0<\/mtd><mtd>0<\/mtd><\/mtr<><mtr>010<\/mtr><mtr>xy1<\/mtr><\/mtable>\u23a5\u23a1\u23a3\u23a2cos(\u03b8)sin(\u03b8)0\u2212sin(\u03b8)cos(\u03b8)0001\u23a4\u23a6\u23a5\u23a1\u23a3\u23a2100010\u2212x\u2212y1\u23a4\u23a6\u23a5\u23a1\u23a3\u23a2xy1\u23a4\u23a6\u23a5=\u23a1\u23a3\u23a2100010xy1\u23a4\u23a6\u23a5\u23a1\u23a3\u23a2cos(\u03b8)sin(\u03b8)0\u2212sin(\u03b8)cos(\u03b8)0001\u23a4\u23a6\u23a5\u23a1\u23a3\u23a2001\u23a4\u23a6\u23a5=\u23a1\u23a3\u23a2100010xy1\u23a4\u23a6\u23a5\u23a1\u23a3\u23a2001\u23a4\u23a6\u23a5=\u23a1\u23a3\u23a2xy1\u23a4\u23a6