{"id":991,"date":"2020-02-24T21:22:02","date_gmt":"2020-02-24T20:22:02","guid":{"rendered":"https:\/\/innovatiestudio.hku.nl\/?p=991"},"modified":"2020-04-16T12:14:10","modified_gmt":"2020-04-16T10:14:10","slug":"lighting-environments-with-peppers-ghost","status":"publish","type":"post","link":"https:\/\/innovatiestudio.hku.nl\/?p=991","title":{"rendered":"Lighting environments with Pepper’s Ghost"},"content":{"rendered":"\n

When executed well the illusion of Pepper’s Ghost continues to
impress, even in the light of recent improvements in AR. However,
because of the boundaries between the physical and the virtual realities
Pepper’s Ghost images tend to look superimposed in a very artificial
way. One way to create more cohesion between the physical and digital
is to add uniform lighting. <\/p>\n\n\n\n

\"\"
How scene lighting, projection and a physical model of an apartment can come together to create a scene.<\/figcaption><\/figure><\/div>\n\n\n\n

So for a project we’re currently working on we wanted to mix physical
and digital space to create an arcade-like interactive box. One of the
more simple ways to essentially create a hologram that’s placed inside a
physically built environment using a technique known as Pepper’s Ghost<\/em>.<\/p>\n\n\n\n

What’s a Pepper’s Ghost?<\/h2>\n\n\n\n

Pepper’s Ghost is an illusion technique named after English scientist
John Henry Pepper. It used a flat sheet of glass that’s ideally invisible to
the viewer to project a ghostly version of a scene or image on the
other side of the glass.<\/p>\n\n\n\n

So, our way of utilising this technique is essentially pretty simple. We
built a box without a top and an opening in the side to look into. Then
we use a computer monitor and lay it on top of the box, the screen
facing down into the box. Then we place a transparent and reflective
plate in the box at a 45 degree angle to the screen to project the images
displayed on the monitor into the physical space. At it’s core, there
isn’t much more to it than that!<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n
\"\"
It’s basically just a box, a monitor and a plate of glass!<\/figcaption><\/figure><\/div>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n

One interesting thing about this technique is that anything you project
this way is placed on a specific plane. This plane starts at the
intersection point of the glass plate and the monitor screen and goes
straight down as long as the plate is placed properly at 45 degrees.<\/p>\n\n\n\n

We want to place this projection plane somewhere in the middle of the
room to create depth. The box had to go deeper than the projection
plane. In our case. That meant we didn’t use about a third of the
monitor for the projection, so we decided to use it in a different way.<\/p>\n\n\n\n

Dynamically lighting the scene<\/h2>\n\n\n\n
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