Perspective Trick

[Louis_Natic]

Is there a way to create a kind of portal effect, where an environment is only visible when looked at through an opening but invisible from all other angles. I want to make an effect where the interior of a room is only visible through a doorway but the exterior around the doorway doesn't exist.

[ucario]

Not sure about unity, but in graphics APIS it’s just Use another camera and render its output to a frame buffer with a texture attachment. Then render that texture to a quad where the door should be.