change camera with gradient effect

I have 2 camera on scene. How can I do to change camera view with a gradient effect?

If you want to make parts of both cameras visible at the same time I can only think of a postprocessing shader. If you don’t have unity pro I can only imagine a dirty hack with meshes in front of the camera (and changing the cameras through its dept setting).

You could do it this way, if you’re willing not to have the cameras on screen at the same time, but separated by only one frame…

Animate a black plane sweeping in whatever direction you want from offscreen, stopping right in front of the camera.

Meanwhile, you have a similar plane set up in front of your second camera.
When the first camera is covered, switch cameras, and move the second plane from in front of the second camera.

Do this quick enough, and the user might not even notice that only one camera was showing at a time.

After a little bit of research I found the solution. As usual, someone had already raised the issue and he solved brilliantly … Thanks