Interactive visual effects by Karl Sims, 2018

This exhibit presents various fluid flow, particle systems, and image processing simulations that react to visitors as they move in front of a display. A video image of the participants is augmented with special effects to give the impression that they are in the same environment as the effects.

Flow is on display and open to the public in the CSAIL lobby of the Frank Gehry-designed MIT Stata Center. This project was commissioned by CSAIL, the Computer Science and Artificial Intelligence Laboratory at MIT.

A Kinect depth sensor detects the shapes of people in front of the display, and allows them to manipulate the simulations with their gestures and motions. The exhibit cycles through 10 effect modes with different simulations and visual effects, each lasting about one minute. The cycle of effects varies from day to day, so your experience may differ depending on when you visit. Photos from a subset of these effects are shown here.

This Fluid Flow Tutorial provides some technical details on the real-time fluid simulations used for this exhibit.

flow exhibit: squirting virtual ink

In this effect, participants see a mirrored image of themselves augmented with virtual colored ink that squirts from their hands and other detected protrusions.

flow exhibit: colored fluid layers

A spectrum of fluid layers with different densities is mixed up by your movements. Gravity affects each density differently and eventually pulls them back to their stable layered state.

    flow exhibit: cellular waves

Colored waves propagate away from your moving edges.

flow exhibit: paint swirls

Inspired by van Gogh, this swirling paint effect is generated from your image and motions. Particle systems are used to render brush strokes, and their dynamics are controlled by a fluid flow simulation.

flow exhibit: finger paint rays

Moving hands paint the screen with rays of colored light.

    flow exhibit: blue waves

In this effect, your motions generate waves in a simulated liquid that propagate across the screen and reflect against the sides.

To the right, the shapes of participants are injected into a fluid flow simulation, causing their colors to swirl away based on their motions. The colors slowly change while they flow to create a range of hues.


Karl Sims developed the simulation and visual effects software for this exhibit using C, OpenGL and OpenCL, which runs on a Linux computer with an NVIDIA Titan Xp graphics card. Jesse Gray of IF Robots developed the Kinect camera and depth sensor interface.

Thanks to the MIT CSAIL team for commissioning this project, including Una-May O'Reilly, Charles Leiserson, and Daniela Rus.

flow exhibit: psychedelic flow

flow exhibit: light swirls

Rays of blue light are generated from liquid shapes that swirl from the motions of users.

flow exhibit: lava lamp

This "lava lamp" effect puts you inside a simulation of upward moving orange blobs colliding with downward moving blue blobs. Your motions can mix up the colors, but viscous forces slowly merge similar colors back into larger shapes.

    flow exhibit: centipede

In this "centipede" effect, the images of participants are replicated into segmented time-delayed patterns.

Back to other work by Karl Sims

© 2018, Karl Sims, All rights reserved.