鏡面反射常數

html,
body,
svg {
  height: 100%;
}

<svg viewBox="0 0 420 200" xmlns="http://www.w3.org/2000/svg">
  <filter id="specularLighting1" x="0" y="0" width="100%" height="100%">
    <feSpecularLighting in="SourceGraphic" specularConstant="1.2">
      <fePointLight x="60" y="60" z="20" />
    </feSpecularLighting>
  </filter>
  <filter id="specularLighting2" x="0" y="0" width="100%" height="100%">
    <feSpecularLighting in="SourceGraphic" specularConstant="0.8">
      <fePointLight x="60" y="60" z="20" />
    </feSpecularLighting>
  </filter>

  <rect x="0" y="0" width="200" height="200" filter="url(#specularLighting1)" />
  <rect
    x="220"
    y="0"
    width="200"
    height="200"
    filter="url(#specularLighting2)" />
</svg>