Adapting the PIC/FLIP fluid simulation method to produce a LEGO water animation & evaluating its performance

Abstract: Fluid simulation in computer graphics is a well-researched field used to simulate water in different ways. Although computer graphics techniques in this area usually aim towards creating realistic representations, they can also deviate to create stylized animations of water that adopt different aesthetics whilst maintaining certain aspects of realism. Recently, voxel-style graphics have emerged as a popular style in video games and movies. One example of this style is the voxel-style water that appears in the The LEGO Movie(2014),where moving masses of water are composed of LEGO bricks. Voxel-style water simulations usually rely on simple mathematical models, which leave room to explore the possibility of using dynamic fluid simulations to produce voxel-style graphics animations like this one. This work adapts a PIC/FLIP, a dynamic fluid simulation method, to produce a LEGO-stylized animation of water, rendering the result using Blender. The LEGO bricks are colored in gradients of blue and white with a method that emulates ’whitewater’, which occurs when turbulent water traps air bubbles inside and creates. A section of the fluid simulation was computed on the GPU as a method of improving performance. The performance of the implementation is measured in terms of time taken to simulate the fluid and render the animation. This is tested for a combination of fluid simulation parameters. How these parameters affect the visuals of the resulting LEGO fluid and performance is evaluated. The results show that the GPU optimisation yields modest improvements in performance for the simulation and rendering process and that PIC/FLIP parameters can be used to manipulate the visuals of the LEGO fluid in different ways. Varying the parameters also significantly change the amount of time required for the rendering and simulation process.