Windowed simulation in fluid flows

A computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to model a surface of a fluid in motion, by performing the steps of:

• for simulating a fluid flow, the method comprising:
• dividing a fluid into a plurality of coarse voxels at a first resolution;
• simulating the fluid flow associated with each coarse voxel in the plurality of coarse voxels at the first resolution;
• defining a three-dimensional window that includes a portion of the coarse voxels;
• dividing each coarse voxel in the portion of the coarse voxels into a plurality of fine voxels at a second resolution;
• 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 first resolution.

The computing system of claim 15, further comprising:

• calculating a first volume associated with the portion of course voxels by summing volumes for each coarse voxel in the portion of course voxels;
• calculating a second volume associated with the portion of course voxels by summing volumes for each fine voxel that lies within any of the course voxels in the portion of course voxels;
• calculating a difference between the first volume and the second volume;
• selecting at least a portion of the fine voxels;
• and
• adding a portion of the difference to each fine voxel in the portion of fine voxels.

A computing system, comprising:

• a memory that is configured to store instructions for a program;
• and
• a processor that is configured to execute the instructions for the program to simulate a fluid flow, by performing the steps of:
• dividing a fluid into a plurality of coarse voxels at a first resolution;
• simulating the fluid flow associated with each coarse voxel in the plurality of coarse voxels at the first resolution;
• defining a three-dimensional window that includes a portion of the coarse voxels;
• dividing each coarse voxel in the portion of the coarse voxels into a plurality of fine voxels at a second resolution;
• 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 first resolution.