Show simple item record

dc.contributor.authorGoldade, Ryan
dc.contributor.authorAanjaneya, Mridul
dc.contributor.authorBatty, Christopher 17:57:06 (GMT) 17:57:06 (GMT)
dc.descriptionPermission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from © 2020 Copyright held by the owner/author(s). Publication rights licensed to ACM. 0730-0301/2020/7-ART43 $15.00
dc.description.abstractWe propose to enhance the capability of standard free-surface flow simulators with efficient support for immersed bubbles through two new models: constraint-based bubbles and affine fluid regions. Unlike its predecessors, our constraint-based model entirely dispenses with the need for advection or projection inside zero-density bubbles, with extremely modest additional computational overhead that is proportional to the surface area of all bubbles. This surface-only approach is easy to implement, realistically captures many familiar bubble behaviors, and even allows two or more distinct liquid bodies to correctly interact across completely unsimulated air. We augment this model with a per-bubble volume-tracking and correction framework to minimize the cumulative effects of gradual volume drift. To support bubbles with non-zero densities, we propose a novel reduced model for an irregular fluid region with a single pointwise incompressible affine vector field. This model requires only 11 interior velocity degrees of freedom per affine fluid region in 3D, and correctly reproduces buoyant, stationary, and sinking behaviors of a secondary fluid phase with non-zero density immersed in water. Since the pressure projection step in both the above schemes is a slightly modified Poisson-style system, we propose novel Multigrid-based preconditioners for Conjugate Gradients for fast numerical solutions of our new discretizations. Furthermore, we observe that by enforcing an incompressible affine vector field over a coalesced set of grid cells, our reduced model is effectively an irregular coarse super-cell. This offers a convenient and flexible adaptive coarsening strategy that integrates readily with the standard staggered grid approach for fluid simulation, yet supports coarsened regions that are arbitrary voxelized shapes, and provides an analytically divergence-free interior. We demonstrate its effectiveness with a new adaptive liquid simulator whose interior regions are coarsened into a mix of tiles with regular and irregular shapes.en
dc.description.sponsorshipThis work was supported in part by the Natural Sciences and En- gineering Research Council of Canada (RGPIN-04360-2014), the Rutgers University start-up grant, and the Ralph E. Powe Junior Fac- ulty Enhancement Award. We would like to thank Cristin Barghiel and SideFX for their generous software donation and Ryoichi Ando for his insightful discussion on comparing our constraint method with stream functions.en
dc.publisherAssociation for Computing Machineryen
dc.relation.ispartofseriesACM Transactions on Graphics;
dc.subjectreduced modelen
dc.titleConstraint bubbles and affine regions: reduced fluid models for efficient immersed bubbles and flexible spatial coarseningen
dcterms.bibliographicCitationRyan Goldade, Mridul Aanjaneya, and Christopher Batty. 2020. Constraint bubbles and affine regions: reduced fluid models for efficient immersed bubbles and flexible spatial coarsening. ACM Trans. Graph. 39, 4, Article 43 (July 2020), 15 pages. DOI:
uws.contributor.affiliation1Faculty of Mathematicsen
uws.contributor.affiliation2David R. Cheriton School of Computer Scienceen

Files in this item


This item appears in the following Collection(s)

Show simple item record


University of Waterloo Library
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
519 888 4883

All items in UWSpace are protected by copyright, with all rights reserved.

DSpace software

Service outages