In 2007, because of reduced staffing due to Halloween falling in the middle of the week, we needed a new attraction to replace the high-volunteer-count Madame Sarita's Spirit Parlour attraction. This is what we came up with:

Save Madame Sarita

Save Madame Sarita is an installation-based video game with custom game controllers which allows kids to, instead of watching a show, become part of the action themselves.

The kids each took on different roles in their quest to save Madame Sarita from the clutches of Marius Blackwood's specter: the Mystic, the Mage, and the Medium.

Each role had a different set of controls to play the game with, and each had a different responsibility for success in this cooperative game. They all had to work together if they were to have any hope of defeating Marius Blackwood.

The Controls

There were three custom controls for Save Madame Sarita:

The Palantir of Abyssinia

The Palantir is a crystal ball filled with water from the river Styx, which glows green with a strange, unnatural light. The "Mystic" player waves his or her hands over it to generate mana for the other players to cast spells from. The Mystic player doesn't even touch anything; just waving their hands over the crystal ball would cause the mana meter on the screen to accrue more power.

Casting Cards of Marie Laveau

These four cards sat on the table, glowing with their own eerie light. The "Mage" player would cast spells into the spirit world by placing her hand in mid-air over the card. Each card did something different.

The Skull of Rasputin

This crystalline skull grins horribly as the "Medium" player holds it in midair. The skull is the team's link into the spirit world, and is used to target the spells being cast against the enemies who seek to keep Madame Sarita prisoner. The Medium could wave the skull around in the air, or slide it around on the table, to move a targeter on-screen.

The Spells

All the players work together to cast spells into the spirit world. There are four spells they can cast:

Valour	Abjuration	Knights
When the Mage passes her hand over this card, it sends a burst of fire into the spirit world, destroying anything with a physical form, like cultists or bats. Above, there is a spider attack which can be repulsed by the Valour spell.	When the Mage passes her hand over this card, it sends a surge of mystical radiant energy into the spirit world, disrupting the forms of the undead, such as the evil specter that is attacking in the screenshot above.	When the path ahead is unclear, the Mage can pass her hand over either the "Sinister" or the "Dexter" knight to choose the path to take, as shown in the screenshot above.

The Installation

The installation was built over the course of a couple of weeks using a large wooden frame and hardboard paneling to create a victorian window-box look. The walls are decorated with a baroque, embossed wallpaper that looks awesome, and rich, deep crimson and gold curtains cordon it off.

A faux windowframe made of foam was created and immediately behind it, we created a four-foot-wide rear projection screen using a three-dollar shower curtain. (We were shocked to see how perfectly such a cheap shower curtain worked as a rear-projection screen - it really did emit a clear, crisp picture!)

We set up an LCD projector behind the installation to throw the game graphics onto the screen. The game itself was created using NewTek Lightwave for the 3D models, Adobe Flash for the textures, and Adobe Director for the interactivity.

Making the Magic

The controls acheived a very other-worldly feel, since they did not have any apparent connection to anything. There were no cables, no cords, and you didn't even have to touch them, or touch them to a surface. They seemed to understand your very gestures. Many people were amazed, unable to figure out how they worked.

For instance, some people guessed that the skull had a mouse in it, but then were shocked when they realized you could pick it up off the table and it still worked. We really pulled off some magic with this one.

Here's the secret to how it works. The controls are read by the computer in exactly the same way you would read them: by looking at them.

Hidden high above the rear projection screen is an Apple iSight camera which is watching the play area. It's smart enough to discern light from darkness, and is even able to pick out objects to distinguish them from each other in its view frustrum.

Because the Spirit Parlour was shrouded in darkness, but the controls were lit up, they were easy for the computer to pick out and track. So, when the Mage passes her hand over one of the lit-up casting cards, that area of the camera view would suddenly go dark from bright, and the computer could trigger the spell. When the Mystic passes her hands over the crystal ball, it would flicker between green and black to the computer, so it could add mana each frame it was different. And since it could track the position of the color blob of Rasputin's Skull, it could track where the Medium was holding the skull, even if it was lifted off of the table.

The key was calibrating the game correctly. In the photo to the right, you can see the calibration screen we built in, showing the camera's view of the action. By specifying the positions to watch for the Casting Cards and the Palantir, and specifying the color to look for on the Skull, the computer learned enough to allow the players to control the game.

See It In Action

Here's some footage of the game actually being played:

Of course, we also had our Magic Mirror going, as well as our usual array of carnival games. See the previous year pages for more information on these attractions.