combining the textures from two frame buffer objects


I have created two frame buffer objects, one is used to render the 3d world and one is used to render the ui. The strategy being if I change the ui I don’t want to re render all the 3d if I don’t have to. My problem is not is how to combine these such that I can display them both. The ui frameTexture has transparency where it is not drawn.

At the moment I have another shader where I try and render both frame textures on to a quad, one after each other. But this only didsplays one, probably due to them haing the same depth.

Is there a better strategy for doing this?

You need to render two quads, the latter with blending enabled. The default framebuffer doesn’t need a depth buffer, but if you can’t control that just disable depth tests and writes.