We present a visualization technique for simulated fluid dynamics data that visualizes the gradient of the velocity field in an intuitive way. Our work is inspired by rheoscopic particles, which are small, flat particles that, when suspended in fluid, align themselves with the shear of the flow. We adopt the physical principles of real rheoscopic particles and apply them, in model form, to 3D velocity fields, by extension of a technique due to Bretherton. By simulating the model behavior and reflectance of these particles we are able to render 3D simulations in a way that gives insight into the dynamics of the system. The results can be rendered in real-time, through a combination of pre-computations and fast ray-tracing on the GPU, allowing the user to inspect the simulation from all perspectives. We demonstrate our method on several different simulations, showing their complex dynamics in the process. We also explore both the accuracy and the limitations of the model dynamics.

No previous knowledge of particle dynamics in fluids or their governing equations will be assumed. The presentation will include emphasis on an open mathematical calculation of interest remaining to be tackled.