Drop (2001)

Prototype: 48" x 48" x 6" box, 36" x 24" x 48" interface. 

Installation: 15' x 15' x 12' minimum room.

Drop is an immersive interactive installation that combines actual and simulated fluid dynamics to explore overlappings of real and virtual.

Part of a darkened room is filled with a shallow pool of water. A computer- generated wireframe visualization of a liquid surface is projected onto the water. The rendered fluid surface undulates and reflects on to surrounding walls, the natural slight perturbations in the actual water adding to the blurring of real and virtual. An ambient soundscape based on water sounds is generated in real-time by viewer behavior.

Viewers trigger virtual drops that produce simulated ripples on the pool of real water. Interaction with the piece is intuitive, requiring no visible interface, using only the movement, and stillness, of one’s body. In opposition to the dominant modes of interactive art, drop encourages slowness, quiet, and meditative exploration.


Viewers’ locations are mirrored by glowing drops on the ceiling above the pool. If a viewer stands still, the corresponding drop expands until the viewer moves or it gets too big, at which point it detaches and ‘falls.’ A brief instant passes, and then simulated ripples appear and dissipate in the pool of water beneath. Ripple size is determined by viewers; the longer they are still, the bigger the drop. The ripples are actually the deformation of a 3D vertex mesh; multiple viewers can trigger drops at the same time, combining and intersecting ripples.

The ambient soundscape is generated in real-time by viewers’ interactions with the piece. Tracked movement in the space produces washes of sound from waveform manipulations analogous to disturbances in water currents. The experience for viewers is meant to suggest moving through an invisible sonic liquid. These sounds are relatively quiet and subtle – drops and ripples produce more noticeable sound events, whose quality, volume, and duration correspond to the size of the drops triggered by viewers.


This installation investigates the uncanny overlappings of simulated and real that are becoming increasingly common in our technologized lives. Water embodies a natural, complex, and elemental force and is therefore a difficult, and perhaps disquieting, candidate for simulation. Among most of us, even technophobes, there is a fascination with the power of technology to imitate the real; is that fascination with its verisimilitude or, rather, the slippage or gap between actual and simulacrum? Artificiality has its own powerful draw, and the stylized reduction of the fluid simulation to its skeleton also references how we might fetishize technology’s limitations and peculiar forms of translation. Our unavoidable tendency to see cause and effect is responsible for the entire system to work as an experience. In the gap of the drop ‘falling,’ this piece reminds us that, as in all technological simulations, it is the viewer that keeps this thread alive.


The three-dimensional wireframe mesh is calculated and rendered continuously by fluid simulation software written in Java3D and OpenGL. The interface software, running on a second computer, is written in Macromedia Director Lingo and use video tracking to transmit the movement of viewers and drop coordinates. The interface software also uses a video projector to show drop formations on the ceiling or a suspended scrim. A third computer handles sound generation using Cycling74’s Max/MSP. Another, higher-resolution video projector, or several in tandem, overlays the mesh on to the actual water. The water pool is treated to act as a projection surface and uses recycling pumps for cleanliness.


As well as substituting a mouse and screen for the full-scale motion tracking interface, the prototype has no real-time sound and a low-complexity ripple simulation. Illustrations show the installation at full scale.

Using Format