Ok, dann nimm immer das gleiche polygon, und drehe es so wie du es brauchst!

<?xml version="1.0" encoding="utf-8"?>
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0" y="0" width="500" height="500" xml:space="preserve" preserveAspectRatio="xMidYMid meet">
  <defs>
    <linearGradient id="grad1" x1="0%" y1="0%" x2="0%" y2="100%">
      <stop offset="0%" style=";stop-opacity:0" />
      <stop offset="100%" style="stop-opacity:1" />
    </linearGradient>
  </defs>
  <g transform="matrix(0.28053959,0,0,0.28053959,109.73006,109.73077)">
    <g>
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "        id="polygon4" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(20 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "  id="polygon6" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(40 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "  id="polygon8" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(60 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "     id="polygon10" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(80 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon12" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(100 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon14" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(120 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "   id="polygon16" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(140 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "  id="polygon18" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(160 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon20" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(180 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon22" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(200 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon24" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(220 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "   id="polygon26" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(240 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "   id="polygon28" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(260 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon30" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(280 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon32" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(300 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "     id="polygon34" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(320 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "   id="polygon36" style="opacity:0.2" fill="url(#grad1)" />
    </g>
    <g transform="rotate(340 500 499.999)">
      <polygon points="572.223,-387 500,499.999 427.777,-386.999 "    id="polygon38" style="opacity:0.2" fill="url(#grad1)" />
    </g>
  </g>

</svg>

Aber vielleicht hast du ja einen Tipp für mich, wie ich "formeltechnisch" die notwendigen Parameter für <linearGradient> berechnen kann?

Was meinst du?