Vertical scale shader for osgEarth 3.x

gistfile1.txt

    <terrainshader>
        <code>
            <![CDATA[
               #pragma version 330
               #pragma vp_location vertex_model
               #pragma vp_entryPoint verticalScale
               uniform float scale = 1.0;
               vec3 vp_Normal;
               float oe_terrain_getElevation();
               
               void verticalScale(inout vec4 vertex)
               {
                   float elev = oe_terrain_getElevation();
                   vec3 offset = vp_Normal * elev * (scale-1.0);
                   vertex.xyz += offset;
               }
            ]]>
        </code>
    </terrainshader>