Copying the Depth Buffer into a Texture

Greetings everyone.

I'm working with JME for the first time and for an effect I am trying to create I need to grab the depth buffer.  However after looking through the API and some of the passes in com.jmex.effects.glsl for a while I have not been able to find anything to accomplish this. 

I'm figuring at this point I'll need to work with LWJGL to grab the depth buffer and turn it into a texture.  Any tips on that would be appreciated if that is the route I need to go.

The DepthOfFieldRenderPass renders the depth buffer to a texture using a shader (i believe, at first glance). Also, look into the Debugger class as it’s used in DebugGameState.

The DepthOfFieldRenderPass does use a shader to render the depth because it needs to alter them.  Useful for that pass but otherwise a waste rendering everything an additional time.

The Debugger does have a method (drawBuffer) that set us in the right direction.

A texture's rttSource field need to be set to the depth buffer, like so: