Seeing the transition to 4th and 5th density

What will it be like when we transition to the 4th and 5th dimensions? I have heard we will still be able to see and interact with those still in the 3rd and their environment, at least for a period of time, whilst being able to have our own beautiful and amazing 5th dimension experience of the world. How do you see it all playing out or appearing to us? I have heard you say it will just be a shift in our perspective. Are we shifting our perspective or is the planet shifting its perspective? If its the former why wouldn't the people that are choosing to stay in 3D just carry on with their lives indefinately instead of crossing over?