HOLOGRAPHIC CHARACTERS IN PHYSICAL SPACE - PEPPERS GHOST ILLUSION

Just as in Plato's Cave, reality is percieved and decerned in the brain of the believer in relation to what has already been learned and experienced.
I found this excert from MIND magazine online at http://www.jstor.org/pss/2247778.
Shurman is describing Aristotle's view of Metaphysics and intellegence, which suggest that intellegence and conclusions of 'reality' go hand-in-hand with a subjects modes of thought and sensory evaluation.

The job of an illusion is to fool ones senses into perceiving reality. The believability of an illusion depends on the accuracy of application and the satisfaction of appropriate senses.

Brief History of Pepper's Ghost

Pepper's Ghost Effect has been used since 1816 to create translucent ghost-like characters in theatre scenes. It has been adapted and used by carnivals, theme parks, movie makers, and other sorts of magicians since then.

Below is a scene from "Diamonds are Forever" where they recreate the famous "Girl to Gorilla" freak show attraction. The original illusion depicts an image of a girl (reflected by a glass pane) morphing into the physically present gorilla, by use of lighting fades on the respective characters.

It is interesting to note that although a Peppers Ghost illusion is not technically concidered to be a hologram, when well constructed and thought out, "You can easily convince the general pulic that you're using holograms"[1].

Making a Pepper's Ghost
When creating a Peppers Ghost style hologram there are many important factors to concider so that the audience is intrigued and taken in by the illusion.

Considerations of character, environment/setting, lighting, interaction, sensory requirements and other practical elements, such as focal length, determine the effectiveness of the outcome.

In short the audience should percieve a holographic character which resides in physical space. It needs to be believable to a point where the audiences' disbelief is suspended and they invest in the hypothetical premise of the narrative.

Focal length
An important concept for creating a character which resides believably in the physical scene, at the right depth, is to have the projected image (light) at a similar distance from the reflective screen (glass pane) as the location it is to appear to occupy in viewed physical space.

In this small mock up I have used two panes of glass and two iterations of the same character (near and far) so that the character appears to reside near the trees in the physical scene (in the further pane) then flash forwards to the viewer in the closer pane. When viewing this illusion in the apparatus directly, the audiences eyes converge at different focal lengths for each pane. This helps to satisfy occulomotor depth cues [2], which helps to subdue disbelief further.

Mannequin (3D Prop) or Light Projector?
There are pro's and con's for each of these methods. When using a traditional prop it can be hard to mechanise the character in a way that depicts natural movement. However, because you are projecting light onto a three dimensional object this can satisfy some linear parallax issues. The light projector method draws its strength mainly from the versatility of what you can project/depict and the sort of movement you can endow your characters with. ...Ultimately, this is a decision you must play around with to see what will work best for you.

Relation to the environment
Size of the character is important. If you have a human character who is as big as a house in your physical scene then this may interfere with believability of the narrative.
Also, you must make sure to choose the right aesthetic qualities for your subject and environment so that they match the theme of your intended narrative. Eg. I dont think Vlad the Impaler would be a beliveable character if he was wearing pink Chuck Taylors and a Slayer Tshirt whilst wandering the halls of his castle. ....Intriguing perhaps.??

Audio sensory
Having matching audio tracking with your hologram will help your audience further believe in your scene. This is an important element as humans generally percieve thier reality, not via visual input alone, but by a mix of sensory stimulis and evaluative thought.
Speaker systems (etc) should be placed so that the audience percieves the sound to be coming from the character.

Interaction
By timing a looped scene to coincide with audience arrival, or triggering it as new subjects enter, can add to the illusion of reality by suggesting interaction between audience and characters. I can see great scope for the use of motion/colour tracking and real time video conversion and display, to be integrated with this illusion to heighten the immersive experience for the viewer.

Other practical concerns

• When using an LCD projector you will have to buy new lamp bulbs fairly often (depending on how often it is running).
• image space and set probably have to be separated from viewing area for safety and to avoid tampering from sneaky hands.
• Acrylic is a good substatute for glass for safety, but is prone to bend and buckle when not supported correctly. This will distort your image.
• Amount of light projected, and the scattering thereof [2], will determine how translucent your character appears to the viewer and will enhance some of the depth cues for your projected 3D character.
  

Conclusion

This is an effect which has played an important, yet somewhat illusive role in pop culture history and entertainment. The advent of new technologies which can be integrated to enhance this illusion leave plenty of scope for it to be used and adapted in the future as we ride the wave of new technologic thought and technological expansion.

References

[1] http://www.phantasmechanics.com/pepper.html [2]An Introduction to Computer Graphics and Creative 3D Environments. B. G Blundell, 2008. [3] http://www.doombuggies.com/secrets_ballroom.php [4] http://www.sciencedaily.com/releases/2007/04/070411170904.htm “Wired For Sound: How The Brain Senses Visual Illusions”[5] http://www.cfar.umd.edu/~fer/optical/ “Optical Illusions”. [6]PSYCHOLOGICAL REVIEW Mind.1898; VII: 441-442

TRANSYLVANIA BLACKLIGHT MINIGOLF

SCALE DRAGON FRAME 1=20

I bought some wire ties, a hot glue gun and started glueing together some shapes for his frame.
I used the shape of the ties with some chopping and a bit of tricky bending manoeuvres and ended up with this guy.

When a player sinks a ball in the hole beside his rock he will slide up from behind a 1.5m - 2 m rock embankment with his wings unfurling and stretching up toward the roof (2.5m up from the rock), and learching out over the course.

Each wing will span out 4m -5m along the wall its close to, sort of wrapping around the course/players).

A convincing flap or two of his wings (which are to be made out of stretchy fabric and latex), a smoke machine billowing smoke from the mouth and nose, and syncronised dragon roar soundtrack would be an entertaining and add to the final resolve. ...No mean feat.

I thought in stead of having flames (OSH says no) we could use flickery orange and red leds to illuminate a portion of the smoke around the dragons mouth (from inside the mouth pointing out). Add a subtle flame whistling in the audio track -perhaps one eminating from a speaker in his head for directional accuracy- and this may work well.

When the dragon has finished his movement sequence the surrounding lights will fade out and he will slide back into the darkness behind the rock to wait for the next person to sink this hole.

PEPPERS GHOST ILLUSION - MYSTICOW

After finding plenty of info on Peppers Ghost on the web I decided to have a go myself. This was just to see if I could get the illusion to work on small scale before I create a larger, moving version;

I noticed that the glass I used was too thick so it cast a kind of double image -a reflection on the front of the pane and another on the back of the pane. I suspect that using thinner glass would help sort this problem.

This second iteration of the Pepper's Ghost Effect is done using two panes of glass with alternating illumination of ghost props. This demonstrates that this effect is viable for use in my current Transylvanian Blacklight Minigolf project. Click here to visit our forum.

BACHELOR OF CREATIVE TEACHNOLOGIES (BCT) YEAR 1, 2009

My first year blog, Studiot, was largely destroyed when i migrated from my original FTP Server, so I have put together an installment of the work I did in 2009;

Body Interface Test

Urban Spin - Video Flaneur

Programming - Processing & Java

Situational Shuffle - Project 1

MUSMASH - 1st Year Art Review
http://musmash.blogspot.com/

Walking on Water - City Screens

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CO OPERATIVE IMMOBILITY - THE SUSTAINABLY IMMOBILE LIFESTYLE (ELECTROSMOG FESTIVAL PROJECT)

"The ElectroSmog Festival is a critique of the worldwide explosion of mobility, and an exploration of the new forms of connectedness with us offered to us by network and communication technologies." -www.electrosmogfestival.net/

For our submission we make the comment that the Sustainably Immobile Lifestyle is dependant upon human co operation and sharing as much as the new connections we now have available to us.

PRIMARY

HOW & WHY?

We chose to use boxes, or walled cubes, to represent a stationary environment indicative of an apartment or other confined, contempory living space. Each participant would be confined in their box, becoming dependant on effort sharing and digital networks to interact and survive. We wanted to see how people behave when faced with this problem.

We realised that if we (the participants) used kinetic generators, connected to a light in a different persons box, instead of using the generators to power electronic communication devices, then the light would serve as a visual representation of the co operation and interactions going on between cubes. Thus, providing a metaphorical insight into how we sustain one another in a sustainably immobile lifestyle.

MAKING ELECTRICITY
Apparently, the equasion below describes Farady's Law of Induction (i cant read it but have been told that this is how the magic happens);

Basically, when you rapidly change the polarity of a coil of copper wire you create an electric charge. This, is the fundamental principle driving all sorts of electricity generators. The energy input, in the case of a handheld kinetic generator, is from human movement -not from splitting atoms, burning oil or diverting bodies of water.

Instructions for how to make a simple kinetic generator;

We went out to buy magnets, insulated copper wire, LED's etc, so that we could create our own kinetic generators for particpants to make charge with during the intallation. While we were shopping we found kinetic torches on sale for $6 each, which quartered the price of making these items -Plus they came ready made for us to hack;

BUILDING & MODIFICATIONS
We realised quickly that our two week time schedule and limited budget would make it very tricky and relatively expensive to create multiple, safe electricity generator/storage/regulator systems (to power a laptop or iphone).

We chose to use the gererators and LED's from our $6 torches; extending the wire that leads to the LED so that the handheld generator and LED's could be placed inside separate boxes. We wanted participants inside the boxes to be responsible for generating charge for someone else's box, giving them discretion over how much or little effort they want to invest.
Later in the project we decided to reintroduce an on/off switch to the generator devices, giving greater control over how/when the electricity was used -Would the simultaneous dependance upon and power over another, unseen person incite co operation or nonparticipation? How long would participants allow themselves to be immobile and physically confined? Are humans capable of the contributing if they, themselves, are not benefiting?

We made the frames for our boxes out of some old wood I found which was destined for the fire. On examining this fortunate coincidence we became more aware that reusing materials which have been discarded is fundamental to creating a more sustainable lifestyle, so we decided to minimise our usage of new/purchased items for the rest of the project as much as possible.

We cut, glued and nailed the wooden frames together then realised we needed to choose an appropriate material to make our walls out of - Something to help us convey the meaning of our project and make it interesting to viewer and participant alike...

Discarded newspaper provided an appropriately opaque wall so that; the person in the box could not see out and interact with the outside world directly, the cube would glow when the LED was switched on, it was free and reused. Also, newspaper is loaded with connotations of communication and distribution of information, which lends well to our overall theme.

LIGHT?
Given our decision to use light in portraying our concept, we felt it would give the installation/performance more visual impact to do be done in the dark preceded by a period with the lights on, where audience and participants are able to investigate what is being used and gain an impression of of the connectedness of the individual spaces;



OUTCOME