RenderTexture is a generic rendering target. To render things into it, simply construct a render target, call begin on it, call visit on any cocos scenes or objects to render them, and call end. For convenience, render texture adds a sprite as it's display child with the results, so you can simply add the render texture to your scene and treat it like any other Cocos Node. There are also functions for saving the render texture to disk in PNG or JPG format.