I added a background image sequence by adding an “empty” to the scene in blender 2.8. Now,I want to match the empty where I have attached the images to the same position of the camera,but I see that I can't move the single vertex of the square. When I move one vertex,all the vertices move together. Is there a way to move only one vertex at a time ? in this way I will be easier to match perfectly the empty's square with the camera's square. thanks.
If you want your reference image to align with the camera, setup the camera to use a background image.
In 2.80 Background Image options have been added to the camera, this allows you to keep the image aligned with the camera view even if you move the camera.
To ensure the image fills the camera view you need to set the render resultion to match the aspect ratio of the reference image.