Keystone correction how to?

[Didaktik]

I display a picture projector. The projector is at an angle to the wall. This gives the vertical keystone.

Advise how to easily adjust or correct them in 3D?

I tried to change the camera angle, but the picture crawls.

Perhaps it is right to make a render to texture? A polygon textures have to tilt or stretch in 3D space?



The projector has a Keystone adjustment. But I think that 3D will be better.

p.s. I create 3D cubes mapping on real cubes.

[Didaktik]

CreateRenderTexture probably not suitable for this purpose.
The fact that I need to catch mouse events that would move 3D objects. And this is possible only in the main camera.

Then you need to use a single camera and rotate and move. But how to compensate for the rotation by a movement?
(Make it so that the object would remain in place)

[Didaktik]

Ok.

I figured out the tilt of the camera. But then pops up another feature. When tilting the camera in cubes becomes too see the bottom.

So you need to still adjust the final texture of the screen.
How can this be done?
Is the screen texture?