The disclosure provides an approach for animating gases. A dynamic model is employed that accounts for stretching of gas vorticles in a stable manner, handles isolated particles and buoyancy, permits deformable boundaries of objects the gas flows past, and accounts for vortex shedding. The model models stretching of vorticity by applying a vector at the center of a stretched vorticle. High frequency eddies resulting from stretching may be filtered by unstretching the vorticle while preserving mean energy and enstrophy. To model boundary pressure, a boundary may be imposed by embedding into the gas the surface boundary and setting boundary conditions based on velocity of the boundary and the Green's function of the Laplacian. For computational efficiency, a vorticle cutoff proportional to a vorticle's size may be imposed. Vorticles determined to be similar based on a predefined criteria and distance threshold may be fused.