It's been a long time since I've posted here! I recently started up an experiment to get from data from a flightsim out into the "real world" to place on a device. It's a MFD that renders video onto a panel in-game, presumably using RTT operations. I want to write a plugin/dll that runs alongside and calls getrendertargetdata() on the texture to pull it back into system memory, and then I can export the data to where I want it to go.

My question is, is there a way to do this from another process? I'm not familiar enough with the rules to know if this is a dead end. I'd have to find the device pointer (Can I use my own?), and then locate the surface/texture somehow. Is this even possible?

I've not done it before, but it's a common enough task for people to "hook directX" - injecting some of your own code between a process and it's DirectX device, so that you can interfere with it from another process, so this should be possible for you.
http://www.altdevblogaday.com/2012/04/02/extravagant-cheating-via-direct-x/