How to apply a shader effect to the sky??

[mong8384]

To apply a shader effect to the sky, how exactly should I do it? I want to apply shader effects to both the terrain and the sky. However, currently only the terrain has shader effects applied. !!

    const char* noiseFrag = R"(		
        uniform float noise; 
        uniform vec2 resolution; 

        float noises(vec2 uv) {
            return fract(sin(dot(uv, vec2(12.9898,78.233))) * 43758.5453);
        }
        void noiseControl(inout vec4 color) {
            //vec2 uv = gl_FragCoord.xy;
            vec2 uv = gl_FragCoord.xy / resolution.xy;
            //vec2 uv = (gl_FragCoord.xy - 0.5 * resolution.xy) / resolution.y;
            float n = noises(uv * noise);
            color = mix(color,vec4(n, n, n, 0.1),0.2);
        }
    )";

struct Acceptor : public osgEarth::ShaderComp::AcceptCallback
{      
    bool operator()(const osg::State& state)
    {       
            return true;
    }
};

osgEarth::VirtualProgram* vp = osgEarth::VirtualProgram::getOrCreate(loaded ->getOrCreateStateSet());
vp->setFunction("noiseControl", noiseFrag, osgEarth::ShaderComp::LOCATION_FRAGMENT_LIGHTING, new Acceptor());

...
...
	osg::Node* loaded = osgEarth::Util::MapNodeHelper().load(arguments, &viewer, uiRoot);	
	osgEarth::MapNode* mapNode = osgEarth::MapNode::get(loaded);
	if (!mapNode) {
		return -1;
	} 	
	osg::ref_ptr<osgEarth::Util::SkyNode> _sky;
	_sky	= osgEarth::Util::SkyNode::create(mapNode);

	if (mapNode->getNumParents() > 0)
	{
		osgEarth::insertGroup(_sky, mapNode->getParent(0));
	}

How to apply a shader effect to the sky??

[gwaldron]

There's no exposed way to do that. You would have to edit the atmospheric shaders directly; these are
SimpleSky.Atmopshere.vert.glsl
SimpleSky.Atmosphere.frag.glsl