Applying shader on camera

Hello, I’m trying to create volumetric clouds with a simple shader, and I don’t know how to use it. As I think it needs to overlap the generated image on the camera’s view. How can I achieve that?

Preview from Shadertoy

You cannot apply a shader on the camera. You need to apply a shader on a geometry. In your case, that geometry could be a rectangle (quad) covering the entire screen. Usually effects like these are rendered after the scene is drawn, so have a look on the FilterPostProcessor and various Filters to get yourself started. These already offer the before mentioned fullscreen quad.