→Vapor Flow: Updated for Update 26
The movement of
gaseous material (either water vapor or CO<sub>2</sub>) across the surface of the object is simulated with a method similar to the one used to simulate [[Temperature Calculation#Surface Temperature|heat diffusion]]. Vapor flows from areas of high density to areas of low density, so the vapor in a single point on the surface map of an object may spread or [https://en.wikipedia.org/wiki/Diffusion diffuse] into nearby points, and the vapor in those points may spread to the first point. Universe Sandbox calculates this diffusion by using the [https://en.wikipedia.org/wiki/FTCS_scheme FTCS method].
amount of vapor of each point on the surface map is then updated based on the results of this diffusion calculation.▼
▲The amount of vapor of each point on the surface map is then updated based on the results of this diffusion calculation.