Method for Generating Simulations of Fluid Interfaces for Improved Animation of Fluid Interactions

Abstract

A method for generating visual representations of interactions between two different materials is provided. The method can be performed using a computing device operated by a computer user or artist. The method includes modeling a primary material as a plurality of first particles and modeling a layer portion of a secondary material as a fluid volume. The secondary material can include a layer portion positioned between the plurality of first particles and an outer portion. At least one boundary condition might be assigned to a boundary positioned between the layer portion and the outer portion, the at least one boundary condition includes at least one pressure value. Values of motion parameters might be determined by applying the at least one boundary condition at the boundary and generating one or more visual representations of the primary material interacting with the secondary material based on the values of the motion parameters.

1 . A motion simulation system for simulating interactions between two different materials, the system comprising:
 at least one processor;   a computer-readable medium storing instructions, which when executed by the at least one processor, cause the system to:
 represent a primary material as a plurality of first particles; 
 represent a layer portion of a secondary material as a grid-based fluid volume, the secondary material comprising the layer portion and an outer portion, the layer portion being positioned between the plurality of particles and the outer portion; 
 assign at least one boundary condition to a boundary positioned between the layer portion and the outer portion based at least in part on pressures of the outer portion and configured to affect the layer portion, the at least one boundary condition comprising at least one pressure value; 
 calculate motion parameters for the primary material based on the plurality of particles and the layer portion; and 
 calculate motion parameters for the secondary material based on the plurality of particles, the layer portion, and the at least one boundary condition, independent of the outer portion. 
   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . The motion simulation system of  claim 1 , wherein the layer portion has a thickness that ranges between 0.1 and 10000 times an average particle size of the plurality of particles. 
     
     
         5 . The motion simulation system of  claim 1 , wherein the layer portion has a thickness that ranges between 10 and 1000 times an average particle size of the plurality of particles. 
     
     
         6 . The motion simulation system of  claim 1 , wherein the layer portion has a thickness that depends on a difference between a first density of the primary material and a second density of the secondary material. 
     
     
         7 . The motion simulation system of  claim 1 , wherein the outer portion of the secondary material is does not move as a result of interaction with the primary material. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . The motion simulation system of  claim 1 , wherein the at least one boundary condition includes a hydrostatic pressure at the boundary configured to exert force on the primary material and the layer portion. 
     
     
         11 . The motion simulation system of  claim 10 , wherein the exerted force affects a shape of the boundary. 
     
     
         12 . The motion simulation system of  claim 1 , wherein the boundary is a first boundary, the at least one boundary condition is at least one primary boundary condition, and the instructions, when executed by at least one processor, further cause the system to:
 assign at least one secondary boundary condition to a second boundary positioned between the primary material and the layer portion, the at least one second boundary condition comprising a free surface boundary condition.   
     
     
         13 . The motion simulation system of  claim 12 , wherein the at least one primary boundary condition comprises a draft force in a vicinity of the first boundary. 
     
     
         14 . (canceled) 
     
     
         15 . The motion simulation system of  claim 1 , wherein the instructions, when executed by at least one processor, further cause the system to:
 calculate a primary velocity field for the primary material, wherein the primary velocity field is configured to store a primary velocity value that indicates how an environment affects motion of the plurality of particles; and   calculate a secondary velocity field for the secondary material, wherein the secondary velocity field is configured to store a secondary velocity value that indicates how the environment affects motion of at least a portion of the secondary material.   
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . The motion simulation system of  claim 1 , wherein the primary material is a liquid and the secondary material is a gas. 
     
     
         20 . The motion system of  claim 1 , wherein the primary material is falling through the secondary material under the influence of gravity. 
     
     
         21 . The motion system of  claim 1 , wherein the primary material is weightless with respect to the secondary material. 
     
     
         22 . The motion simulation system of  claim 1 , wherein the primary material is a gas and the secondary material is a liquid. 
     
     
         23 . The motion system of  claim 1 , wherein the primary material is rising buoyantly through or suspended buoyantly within the secondary material. 
     
     
         24 . The motion simulation system of  claim 1 , wherein the primary material is a solid and the secondary material is a liquid. 
     
     
         25 . The motion simulation system of  claim 24 , wherein the solid comprises hair, cloth, or sponge. 
     
     
         26 . The motion simulation system of  claim 1 , wherein the primary material is a solid and the secondary material is a gas. 
     
     
         27 . The motion simulation system of  claim 1 , wherein the instructions, when executed by the at least one processor, further cause the system to generate one or more visual representations of the primary material interacting with the secondary material based on the values of the motion parameters. 
     
     
         28 . The motion simulation system of  claim 1 , wherein either the primary material or the secondary material is invisible in the one or more visual representations.