feDiffuseLighting filter primitive

You have to use light source with feSpotLight, feDistantLight or fePointLight.
You have to use feComposite, feMerge or feBlend to merge picture and light or apply lighting to in picture.
feComposite give best result with more parameters.

Parameters:

surfaceScale : height of surface.

diffuseConstant : This can be any non-negative number.

kernelUnitLength : One or two positive numbers. ( space or comma as separator )

lighting-color : color value for light

result : name of RGBA raster created

Example of code:

<defs>
   <filter id="MyFilter" filterUnits="userSpaceOnUse" x="0" y="0" width="400" height="400">
      <feImage xlink:href='puzzle.jpg' result='image'/>
      <feDiffuseLighting lighting-color='white' result='spot' surfaceScale="1" diffuseConstant="1" kernelUnitLength="1,1"> 
         <feSpotLight x='200' y='200' z='200' pointsAtX='200' pointsAtY='100' pointsAtZ='0' specularExponent='16' limitingConeAngle='45' />
      </feDiffuseLighting>
      <feComposite in='image' in2='spot' operator="arithmetic" k1="0.5" k2="1" k3="1" k4="0"/>
   </filter>
</defs>
......
<use filter="url(#MyFilter)" x='0' y='0'/>

Figure 1: different values of surfaceScale lighting a turbulence

Figure 2: effects on tiling of plane

Figure 3: effects on pattern

Figure 4: effects on gradient with stop-opacity:0 for one color

Tool: you can change parameters for feDiffuseLighting, feSpotLight and feComposite ( to merge picture and lightning ) and move with mouse lighting on a JPEG or SVG picture.

Example see different values of surfaceScale for feDiffuseLighting on feTurbulence picture.
examples using gradient, using pattern, using tiling of plane

FrontPage feColorMatrix feComponentTransfer feSpecularLightning feDiffuseLightning feSpotLight feDistantLight fePointLight feFlood feImage feTurbulence feTile feMerge feBlend feComposite feGaussianBlur feMorphology feConvolveMatrix feDisplacementMap feOffset