Hologram or Pepper's ghost is an illusion technique used in the theatre, amusement parks, museums, television, and concerts.
We create projection on special foil, glass or piramid to create illusion of an person or object in the space.
Hologram can be created as non interactive or interactive installation .
Usually hologram shows person that can "interact" with viewer or some object.
This is example of small pyramid hologram installation that is used for 3D visualisation of small objects. Usually in museums or shops.