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Patent Application Titled "Advection of Uv Texture Maps in Fluid Flows" Published Online

January 23, 2014

By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C. , by VerticalNews journalists, a patent application by the inventors O'Brien , Michael K . ( Albany, CA ); Hemberger, Allen ( Oakland, CA ), filed on March 15, 2013 , was made available online on January 9, 2014 . The assignee for this patent application is Pixar. Reporters obtained the following quote from the background information supplied by the inventors: "The present invention relates to the field of computer animation and, in particular, to advection of UV texture maps in fluid flows. "In computer animation, fluid flows are typically modeled by dividing the fluid into regions, typically represented as cubic regions, called volumetric elements, or voxels, where each voxel includes a portion of the fluid. The fluid flow, as modeled by the collection of voxels, serves as input to a software application that simulates the fluid flow over time. At specific points in time, the simulated fluid flow is rendered to a 2D image representing a frame of film or video. A collection of these rendered images may then be played in sequence to visualize the fluid flow. The fluid flow may be composited with other visual elements to create a final rendered image. "Each voxel in the fluid flow may be rendered over time by measuring the amount of fluid within each voxel at a given image frame, as determined by the simulation software application. As the simulation progresses, fluid may enter a given voxel at some locations and exit the voxel in other locations. The net volume of fluid in the voxel may increase, decrease, or remain the same from a particular image frame to the next image frame. Each voxel is rendered to a 2D surface, representing the view of a virtual camera, to create the image of the fluid. One drawback with this approach is that volumetric rendering is compute intensive. When simulating large fluid flows, such as the water flowing in a large river, the amount of time needed to create each image frame may be unacceptably long, even when a substantially high quantity of servers are deployed to perform the simulation and rendering of the fluid flow. One possible solution is to increase the size of each voxel in the fluid flow, thereby decreasing the number of voxels in the overall fluid flow that are simulated and rendered. However, a small voxel size is often desired in order to model fine detail of the fluid flow, thereby creating a more realistic and visually pleasing image. "The surface of such a fluid flow may be modeled by computing a height field that defines the displacement of the surface of the fluid over time. For example, when modeling the surface of a body of water, an increasing height field may represent an area of the surface where a wave is developing, while a decreasing height field may represent an area of the surface where a trough is developing. Again, a simulation software application may simulate the surface characteristics, based on changes in the height field over time, and the simulation is rendered at specific points to create a series of images representing the surface of the fluid. One drawback with this approach is that such height field models may provide reasonable simulations for relatively stable fluids, such as an ocean surface, these models may not provide a realistic surface image for rapidly moving fluids, such as the surface of a rushing river." In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "One embodiment of the present invention includes a method for simulating a fluid flow. The method includes dividing a fluid into a plurality of coarse voxels at a first resolution, and simulating the fluid flow associated with each coarse voxel in the plurality of coarse voxels at the first resolution. The method further includes defining a three-dimensional window that includes a portion of the coarse voxels, and dividing each coarse voxel in the portion of the coarse voxels into a plurality of fine voxels at a second resolution. The method further includes simulating the fluid flow associated with each fine voxel in the plurality of fine voxels at the second resolution, based at least in part on the simulation at the coarse resolution. "One embodiment of the present invention includes a method for modeling a surface of a fluid in motion. The method includes selecting a mesh point from a plurality of mesh points that is associated with the surface of the fluid. The method further includes retrieving a first texture element from a set of uv texture maps, and attaching a first displacement value to the mesh point based on the first texture element. The method further includes advecting the first displacement value over a first duration represented by a first quantity of image frames such that the first displacement value remains attached to the mesh point as the plurality of mesh points moves in response to a motion of the fluid. "Other embodiments include, without limitation, a computer-readable storage medium that includes instructions that enable a processing unit to implement one or more aspects of the disclosed methods as well as a computing system configured to implement one or more aspects of the disclosed methods. BRIEF DESCRIPTION OF THE DRAWINGS "So that the manner in which the above recited features of the invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. "FIG. 1 is a block diagram of a system configured to implement one or more aspects of the invention; "FIG. 2 illustrates a coarse voxel and corresponding fine voxels, according to one embodiment of the present invention; "FIG. 3 shows an example of a windowed simulation image frame and a corresponding final image frame, according to one embodiment of the present invention; "FIG. 4 sets forth a flow diagram of method steps for simulating a fluid flow, according to one embodiment of the present invention; "FIG. 5 illustrates a set of properties corresponding with a point on a mesh that is associated with a fluid surface, according to one embodiment of the present invention; and "FIGS. 6A-6B set forth a flow diagram of method steps for modeling the surface of a fluid, according to one embodiment of the present invention." For more information, see this patent application: O'Brien , Michael K .; Hemberger, Allen. Advection of Uv Texture Maps in Fluid Flows. Filed March 15, 2013 and posted January 9, 2014 . Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4859&p=98&f=G&l=50&d=PG01&S1=20140102.PD.&OS=PD/20140102&RS=PD/20140102 Keywords for this news article include: Pixar, Software. Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Politics & Government Week


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