World Creator - Documentation and Support

Related articles:

• Simulation Layers Introduction
  
• General Simulation Layer Information

Overview

The Snow Simulation Layer simulates the evolution of the snow layer over time on the terrain. The system works internally on two separate layers, an upper layer for powdery snow, which is susceptible to diffusion, and a lower unstable layer, which is transformed by avalanches.

Both are affected by melting (powdery snow melts first, as soon as there is no more powdery snow, the unstable snow melts) and, depending on the Powdery/Unstable Ratio parameter, also by precipitation.

The key to properly using the snow simulation is to understand the underlying temperature parameters that affect precipitation and melting. Temperature is primarily calculated from elevation. The Temperature Offset controls the height at which the temperature is 0°. The Temperature Scale then controls how many meters of elevation it takes to change the temperature by one degree (e.g. a scale of 5 means 1° change every 5 meters of elevation).
In addition to elevation, the amount of sunlight during the day also affects the temperature. If enabled, the system will use the global sun settings from World Creator, but you can override them if you wish.

The amount of simulated material is also quite different from the other simulation layers, as the snow simulation can produce additional sediment during the simulation, instead of the fixed amount of sediment that is set at a specified spawn level like in the fluid or sand simulation layers.

Parameters

Global

• Temperature Offset
  The altitude at which the temperature is 0°.

• Temperature Scale
  How many meters of elevation it takes to change 1°.

• Use Global Sun
  Toggles between World Creator's global sun parameter and the layer's custom north value.

• Sun North (only visible is Use Global Sun is disabled)
  The layers custom north value.

• Sun Temperature
  The influence of the terrain's solar exposure on the computed temperature map.

Precipitation

• Strength
  The amount of snowfall in each simulation step.

• Temperature
  The temperature below which precipitation occurs.

• Powdery/Unstable Ratio
  The distribution of powdery/unstable snow in new snowfall. 0 is only powdery, 1 is only unstable snow.

Melt

• Strength
  The power of the melt in each simulation step.

• Temperature
  The temperature at which melting occurs.

Diffusion (powdery layer)

• Speed
  The rate of downward diffusion of the powder layer.

• Rest Angle
  Controls the rest angle at which diffusion stops.

Avalanche (unstable layer)

• Probability
  The probability that an avalanche is formed. Depends on temperature, amount of snow and slope.

• Speed
  The speed at which the avalanches travel downhill.

• Viscosity
  The viscosity/inertia of the avalanche.

• Rest Angle
  The angle at which the avalanche will stop.

• Spawn Level
  In which level the sediment gets added to the terrain.

• Spawn Amount
  The amount of sediment added to the terrain.

Results

base snow simulation

strong snow simulation