Method for simulating combustion in digital imagery with variable pressure conditions

1. A computer-implemented method of simulating an atmospheric phenomenon within a virtual simulation volume, the computer-implemented method comprising:

under the control of one or more computer systems configured with executable instructions, at each time step of a plurality of time steps:

automatically calculating a temperature distribution of the atmospheric phenomenon within the virtual simulation volume based on an assumption of fixed volume; and

automatically calculating a velocity field of the atmospheric phenomenon within the virtual simulation volume, based on an assumption of adiabatic expansion.

2. The computer-implemented method of claim 1 , wherein the atmospheric phenomenon is a combustion event.

3. The computer-implemented method of claim 2 , wherein the combustion event is an explosion.

4. The computer-implemented method of claim 1 , wherein the atmospheric phenomenon comprises a condensation of a vapor into a cloud, fog, or mist.

5. The computer-implemented method of claim 1 , wherein at least conservation of momentum and mass of a physical system are included in continuum mechanics equations used for simulating the atmospheric phenomenon.

6. The computer-implemented method of claim 1 , further comprising simulating a combustion reaction or condensation reaction.

7. The computer-implemented method of claim 1 , further comprising, with a simulated emitter, emitting a material into the virtual simulation volume, wherein the material affects the atmospheric phenomenon.

8. The computer-implemented method of claim 7 , wherein a buoyancy or maximum atmospheric saturation of the material varies with altitude.

9. The computer-implemented method of claim 8 , wherein an ambient pressure or temperature at a boundary of the virtual simulation volume varies with altitude.

10. The computer-implemented method of claim 1 , wherein an ambient pressure or temperature at a boundary of the virtual simulation volume varies with position.

11. The computer-implemented method of claim 1 , wherein automatically calculating the temperature distribution of the atmospheric phenomenon includes simulating at least one of reaction, diffusion, or radiation.

12. The computer-implemented method of claim 1 , wherein automatically calculating the velocity field of the atmospheric phenomenon includes simulating advection based on a velocity field from a previous time step.

13. The computer-implemented method of claim 1 , further comprising:

simulating a first portion of the atmospheric phenomenon having a variable density,

wherein the variable density during the first portion of the atmospheric phenomenon varies in response to a divergence of the velocity field.

14. The computer-implemented method of claim 1 , further comprising:

using a convolution kernel to simulate heat diffusion by blurring at least a portion of the atmospheric phenomenon.

15. The computer-implemented method of claim 14 , further comprising:

deriving the convolution kernel from a heat equation.

16. The computer-implemented method of claim 1 , further comprising generating one or more visual representations of the atmospheric phenomenon based on the simulation.

17. A computer system for generating the one or more visual representations of the atmospheric phenomenon, the system comprising:

at least one processor; and

a computer-readable medium storing instructions, which when executed by the at least one processor, cause the system to carry out the method of claim 1 .

18. A non-transitory computer-readable storage medium storing instructions, which when executed by at least one processor of a computer system, cause the computer system to carry out the method of claim 1 .