Howto modify the projection matrix

Hello,
trying to make this work for two cameras at the same time, so I can project on a floor and a wall from the viewer point of view, which I get from a kinect 2 sensor.

I’ve been going through the code and I see it works by changing the matrix for the viewport… what would be the approach to get 2 cameras with the offaxis matrix?
Should it be possible to use it with a sceneCapture2D and then send it through spout?

Currently I have a project with 2 sceneCapture2D, which sends the render target through spout to the rendering system. But I’m not able to figure out how to apply the matrix to thouse sceneCapture2D.

Any suggestion would be really appreciated!

Antonio.