Mathematical modelling and computer animation Animation of chocolate flow on complex surface Martin Madaras

Intro Fountain model Real flow Flow simulation Fluid mesh Rendering

Fountain model 3D Studio Max Low-res for simulation, High-res for rendering

Real flow Next Limit, authors of renderer Maxwell (using metropolis light transport algorithm for global illuminance computation), more correct than other renderers Disadvantages : Very long rendering time, preview can be made at the moment, but is very noisy XFlow and RealFlow, RealFlow is used in entertainment industry, XFlow in science and technology RealFlow is standalone app, for simulation only (fluid, gas, rigid bodies) Rendering must be made in other programs 3DS Max, Blender,...

Fluid mesh

Flow simulation 1 World in program RealFlow is simuluted with Deamons, which affect behavior of material (gravitation, noisefield, vortex…) There are also Kill Deamons, which can delete particles when they satisfy some conditions (particles are out of camera frustrum, velocity is too high, particle has no neighbours in some range) Geometry can be imported, all faces should be triangles (for better computation) Chocolate has high viscosity and surface tension, these parameters affect time of computation (number of particles had to be lowered) CPU : 4core q6600, time necessary for simulation of 1100 frames was 11 hours

Flow simulation 2 2 phases of simulation. In first is simulation made on particles (number based on emiter settings) In second, mesh is created over particles ( Blob Meshes) Afterwards, mesh can be exported for every frame and imported into another program via plugin. Mesh behaves as normal object Flow simulation computation is very expensive

Import via next limit plugin

Lighting and camera Camera path is ellipsoid spiral spline Rendered with VRay render, Indirect illumination calcualtion Lighting made via HDRI map of interior

Rendering and postprocessing Fountain model was surrouned by cylinder panoramatic photo of chocolate shop. Panoramatic photo was blured for better look Frames joined in open source software Virtual dub and exported into avi, coded with H.264 divx codec

Images