I created a splitscreen-game for two players left and right.
My aim is to change the players view from left/right to up/down.
This is considered to happen with a smooth animation - here is what I achieved:
In the begining two viewports are used as textures for polygons left and right. Their resolution is the half of the screen as it is in the end of the animation.
During the "turn" I have to increase the viewport resolution to the the screen size to fill the polygons with the full horizontal and vertical length. BUT now the computer has to render two viewport of the resolution of the whole screen where as the polygons still display only the half of each. This "waste of render overage" costs resources which can be seen in the fps-decrease (You can follow it in the video very well).
So my question: Is there a way to tell a viewport to render only a certain segment? Or do you have another idea how I can solve this problem?