+" vfrag += emit;\n"
+"\n"
+" if( uMapInfo.z > 0.0 ){\n"
+" float height = fract( aCo.y * 0.1 );\n"
+" float lg = 2.0*length(vec2(dFdx(height), dFdy(height)));\n"
+" vfrag *= 1.0f+(lg*0.2*uMapInfo.z);\n"
+" }\n"
+"\n"
+" oColour = vec4( vfrag, 1.0 );\n"