i can add a custom view over the cocos2d render, but actually want to have the exact oposite: is there a way to renderon a UIView?
Well, you can obtain framebuffer context from CCView and render it into any view you want. Shouldn’t be a problem with both GL and Metal
CCDirector.sharedDirector.view is an UIView. You ought to be able to add it as a child of any other UIView you like. (I do not know, however, how well cocos2d behaves if this is done, but you can try.)