Rendering game engine footage

i am currently working on a project, involving projection mapping, we decided to use blender game engine so we could see any changes in real time. using the game engine i have created some geometry that rotates when a cube come close to it, the problem now is being able to render the screen. is there a function like the screen cast to record the screen while in game so not having to use another program like fraps or camtasia, as this may result in reduced quality of lagging video footage? any help would be very much appreciated

So where exactly do you want to render the screen? If you’re thinking of writing each frame to disk the external software designed to do just that is much faster I believe.

  1. Go to Game -> Record animation.
  2. Select all of the objects in your scene.
  3. Go to the physics panel.
  4. Select Record Animation
  5. Right click on Record Animation and click Copy To Selected.
  6. Press p (start the game)
  7. Stop game/simulation

Frames will now be recorded.

He means to a video,

like screen capping every frame using the bge.

the problem I think is that the gpu renders everything, and does not spit it back at the cpu/hardisk unless you tell it to,

so it would be in the openGL/filter code you would do this?

By recording the game to keyframes, you can use the internal renderer or even cycles. You could copy the frame buffer to an image file every frame, but that is incredibly taxing.
If it has to look like the in-game graphics, then an external screen recorder has to be used. Try Open Broadcasting Software; it’s free and is VERY well optimized with a lot of customization options. It is designed for streaming games, so the file output is low and the effect on performance is also low.

This could be done maybe?