index.md

---

title: diffuseConstant
slug: Web/SVG/Attribute/diffuseConstant
page-type: svg-attribute
tags:
  - Filters
  - SVG
  - SVG Attribute
browser-compat: svg.elements.feDiffuseLighting.diffuseConstant

---

{{SVGRef}}

The diffuseConstant attribute represents the k_d value in the Phong lighting model. In SVG, this can be any non-negative number.

It's used to determine the final RGB value of a given pixel. The brighter the lighting-color, the smaller this number should be.

You can use this attribute with the following SVG elements:

• {{SVGElement("feDiffuseLighting")}}

Example

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

<svg viewBox="0 0 420 200" xmlns="http://www.w3.org/2000/svg">
  <filter id="diffuseLighting1" x="0" y="0" width="100%" height="100%">
    <feDiffuseLighting in="SourceGraphic" diffuseConstant="1">
      <fePointLight x="60" y="60" z="20" />
    </feDiffuseLighting>
  </filter>
  <filter id="diffuseLighting2" x="0" y="0" width="100%" height="100%">
    <feDiffuseLighting in="SourceGraphic" diffuseConstant="2">
      <fePointLight x="60" y="60" z="20" />
    </feDiffuseLighting>
  </filter>

  <rect
    x="0"
    y="0"
    width="200"
    height="200"
    style="filter: url(#diffuseLighting1);" />
  <rect
    x="0"
    y="0"
    width="200"
    height="200"
    style="filter: url(#diffuseLighting2); transform: translateX(220px);" />
</svg>

{{EmbedLiveSample("Example", "420", "200")}}

Usage notes

Value	{{cssxref("number")}}
Default value	1
Animatable	Yes

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• Description of Phong reflection model on Wikipedia