示例
<svg width="800px" height="600px">
<defs>
<filter id="complex-shadow" color-interpolation-filters="sRGB" x="-50%" y="-50%" height="200%" width="200%">
<!-- Take source alpha, offset it by angle/distance and blur it by size -->
<feOffset id="offset" in="SourceAlpha" dx="11" dy="6" result="SA-offset"/>
<feGaussianBlur id="blur" in="SA-offset" stdDeviation="4" result="SA-o-blur"/>
<!-- Apply a contour by using a color curve transform on the alpha and clipping the result to the input -->
<feComponentTransfer in="SA-o-blur" result="SA-o-b-contIN">
<feFuncA id="contour" type="table" tableValues="0 1 .3 .1 0.05 .1 .3 1 "/>
</feComponentTransfer>
<feComposite operator="in" in="SA-o-blur" in2="SA-o-b-contIN" result="SA-o-b-cont"/>
<!-- Adjust the spread by multiplying alpha by a constant factor --> <feComponentTransfer in="SA-o-b-cont" result="SA-o-b-c-sprd">
<feFuncA id="spread-ctrl" type="linear" slope="2.8"/>
</feComponentTransfer>
<!-- Adjust color and opacity by adding fixed offsets and an opacity multiplier -->
<feColorMatrix id="recolor" in="SA-o-b-c-sprd" type="matrix" values="0 0 0 0 0.945 0 0 0 0 0.137 0 0 0 0 0.137 0 0 0 0.49 0" result="SA-o-b-c-s-recolor"/>
<!-- Generate a grainy noise input with baseFrequency between approx .5 to 2.0. And add the noise with k1 and k2 multipliers that sum to 1 -->
<feTurbulence result="fNoise" type="fractalNoise" numOctaves="6" baseFrequency="1.98"/>
<feColorMatrix in="fNoise" type="matrix" values="1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 7 -3" result="clipNoise"/>
<feComposite id="noisemix" operator="arithmetic" in="SA-o-b-c-s-recolor" in2="clipNoise" k1="0.67" k2="0.33" result="SA-o-b-c-s-r-mix"/>
<!-- Merge the shadow with the original -->
<feMerge>
<feMergeNode in="SA-o-b-c-s-r-mix"/>
<feMergeNode in="SourceGraphic"/>
</feMerge>
</filter>
</defs>
<text filter="url(#complex-shadow)" x="30" y="100" font-size="80" font-family="Sans-Serif" font-weight="bold">SVG Filters</text>
</svg>
