<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
<svg width="20cm" height="15cm" viewBox="0 0 800 600"
    xmlns="http://www.w3.org/2000/svg"
    xmlns:xlink="http://www.w3.org/1999/xlink/"
    baseProfile="tiny" version="1.2">
  <title>Spheres</title>
  <desc>Semi-transparent bubbles on a colored background.</desc>
    <defs>
      <!-- Create radial gradients for each bubble. -->
      <radialGradient id="blueBubble" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" stop-opacity="1" />
        <stop offset="25%" stop-color="#cdcdff" stop-opacity=".65" />
        <stop offset="100%" stop-color="#cdaacd" stop-opacity=".75" />
      </radialGradient>
      <radialGradient id="redBubble" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" stop-opacity="1" />
        <stop offset="25%" stop-color="#ffcdcd" stop-opacity=".65" />
        <stop offset="100%" stop-color="#bbbb99" stop-opacity=".75" />
      </radialGradient>
      <radialGradient id="greenBubble" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" stop-opacity="1" />
        <stop offset="25%" stop-color="#cdffcd" stop-opacity=".65" />
        <stop offset="100%" stop-color="#99aaaa" stop-opacity=".75" />
      </radialGradient>
      <radialGradient id="yellowBubble" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" stop-opacity="1" />
        <stop offset="25%" stop-color="#ffffcd" stop-opacity=".65" />
        <stop offset="100%" stop-color="#bbbbaa" stop-opacity=".75" />
      </radialGradient>
      <radialGradient id="background" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="400" fx="250" fy="250">
        <stop offset="0%" stop-color="#ffffee" />
        <stop offset="100%" stop-color="#ccccaa" />
      </radialGradient>
      <linearGradient id="surface" gradientUnits="userSpaceOnUse"
                      x1="-100" y1="200" x2="400" y2="200">
        <stop offset="0%" stop-color="#ffffcc" />
        <stop offset="100%" stop-color="#bbbb88" />
      </linearGradient>

      <!-- Create radial gradients for each circle to make them look like
           spheres. -->
      <radialGradient id="blueSphere" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" />
        <stop offset="75%" stop-color="blue" />
        <stop offset="100%" stop-color="#222244" />
      </radialGradient>
      <radialGradient id="redSphere" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" />
        <stop offset="75%" stop-color="red" />
        <stop offset="100%" stop-color="#442222" />
      </radialGradient>
      <radialGradient id="greenSphere" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" />
        <stop offset="75%" stop-color="green" />
        <stop offset="100%" stop-color="#113311" />
      </radialGradient>
      <radialGradient id="yellowSphere" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="-50">
        <stop offset="0%" stop-color="white" />
        <stop offset="75%" stop-color="yellow" />
        <stop offset="100%" stop-color="#444422" />
      </radialGradient>
      <radialGradient id="shadowGrad" gradientUnits="userSpaceOnUse"
                      cx="0" cy="0" r="100" fx="-50" fy="50">
        <stop offset="0%" stop-color="black" stop-opacity="1.0" />
        <stop offset="100%" stop-color="black" stop-opacity="0.0" />
      </radialGradient>

      <!-- Define a shadow for each sphere. -->
      <circle id="shadow" fill="url(#shadowGrad)" cx="0" cy="0" r="100" />
      <g id="bubble">
        <circle fill="black" cx="0" cy="0" r="50" />
        <circle fill="#a6ce39" cx="0" cy="0" r="33" />
        <path fill="black" d="M 37,50 L 50,37 L 12,-1 L 22,-11 L 10,-24 L -24,10
                              L -11,22 L -1,12 Z" />
        <circle cx="0" cy="0" r="100" />
      </g>
    </defs>
  <g>
    <rect fill="url(#background)" x="0" y="0" width="800" height="600" />
  </g>

  <g transform="translate(200,700)">
    <use xlink:href="#bubble" fill="url(#blueBubble)" />
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="1s" dur="10s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(315,700)">
    <g transform="scale(0.5,0.5)">
      <use xlink:href="#bubble" fill="url(#redBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="3s" dur="7s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(80,700)">
    <g transform="scale(0.65,0.65)">
      <use xlink:href="#bubble" fill="url(#greenBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="5s" dur="9s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(255,700)">
    <g transform="scale(0.3,0.3)">
      <use xlink:href="#bubble" fill="url(#yellowBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="2s" dur="6s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(565,700)">
    <g transform="scale(0.4,0.4)">
      <use xlink:href="#bubble" fill="url(#blueBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="4s" dur="8s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(715,700)">
    <g transform="scale(0.6,0.6)">
      <use xlink:href="#bubble" fill="url(#redBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="1s" dur="4s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(645,700)">
    <g transform="scale(0.375,0.375)">
      <use xlink:href="#bubble" fill="url(#greenBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="0s" dur="11s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(555,700)">
    <g transform="scale(0.9,0.9)">
      <use xlink:href="#bubble" fill="url(#yellowBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="3s" dur="7.5s" fill="freeze" repeatCount="indefinite" />
  </g>

  <g transform="translate(360,700)">
    <g transform="scale(0.5,0.5)">
      <use xlink:href="#bubble" fill="url(#blueBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="3s" dur="6s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(215,700)">
    <g transform="scale(0.45,0.45)">
      <use xlink:href="#bubble" fill="url(#redBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="5.5s" dur="7s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(420,700)">
    <g transform="scale(0.75,0.75)">
      <use xlink:href="#bubble" fill="url(#greenBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="1s" dur="9s" fill="freeze" repeatCount="indefinite" />
  </g>
  <g transform="translate(815,700)">
    <g transform="scale(0.6,0.6)">
      <use xlink:href="#bubble" fill="url(#yellowBubble)" />
    </g>
    <animateTransform attributeName="transform" type="translate" additive="sum"
        values="0,0; 0,-800" begin="2s" dur="9.5s" fill="freeze" repeatCount="indefinite" />
  </g>

  <g transform="translate(225,375)" >
    <g transform="scale(1.0,0.5)" >
      <path d="M 0 0 L 350 0 L 450 450 L -100 450 z"
            fill="url(#surface)" stroke="none" />
    </g>
  </g>
    <g transform="translate(200,0)" >
    <g transform="translate(200,490) scale(2.0,1.0) rotate(45)" >
      <rect fill="#a6ce39" x="-69" y="-69" width="138" height="138" />
      <circle fill="black" cx="0" cy="0" r="50" />
      <circle fill="#a6ce39" cx="0" cy="0" r="33" />
      <path fill="black" d="M 37,50 L 50,37 L 12,-1 L 22,-11 L 10,-24 L -24,10
                            L -11,22 L -1,12 Z" />
      <animateTransform attributeName="transform"  type="rotate" additive="sum" values="0; 360"
                 begin="0s" dur="10s" fill="freeze" repeatCount="indefinite" />
    </g>
    <g transform="translate(200,375)">
      <use xlink:href="#shadow" transform="translate(25,55) scale(1.0,0.5)" />
      <circle fill="url(#blueSphere)" cx="0" cy="0" r="100" />
    </g>
    <g transform="translate(315,440)">
      <g transform="scale(0.5,0.5)">
        <use xlink:href="#shadow" transform="translate(25,55) scale(1.0,0.5)" />
        <circle fill="url(#redSphere)" cx="0" cy="0" r="100" />
      </g>
    </g>
    <g transform="translate(80,475)">
      <g transform="scale(0.65,0.65)">
        <use xlink:href="#shadow" transform="translate(25,55) scale(1.0,0.5)" />
        <circle fill="url(#greenSphere)" cx="0" cy="0" r="100" />
      </g>
    </g>
    <g transform="translate(255,525)">
      <g transform="scale(0.3,0.3)">
        <use xlink:href="#shadow" transform="translate(25,55) scale(1.0,0.5)" />
        <circle fill="url(#yellowSphere)" cx="0" cy="0" r="100" />
      </g>
    </g>
  </g>
</svg>