Variables¶
Precipitation can be attached to any cloud keyframe and will produce rain or snow based on cloud position and thickness.
Rain and snow can be fully customised, from rain speed to snowflake size.
For transparent effects, such as precipitation and lightning to work in Unreal, trueSKYtransluscent needs to be added as a post process material. This should be done automatically. Learn about this here
Keyframe Settings¶
These settings are set on a cloud keyframe, which means they can be interpolated over time.
Variable |
Definition |
Value |
|---|---|---|
Regional |
Whether rain/snow falls only in a specified region, or globally. |
Bool |
Wind affects position |
If the wind should affect the regional area. |
Bool |
Radius (km) |
Radius of the precipitation region. |
Between 0.1 and 1000 km |
Rain - Snow |
How the precipitation will act. 0 = rain, 1 = snow, values in between will share characteristics. |
0.0 to 1.0 |
Strength |
Amount of rain/snow. |
0.0 to 1.0 |
Rain Streaks |
Visual strength of rain streak effect. |
0.0 to 1.0 |
Cloud Rendering Options¶
These global settings affect all precipitation, and will not change over time unless specifically adjusted.
Variable |
Definition |
Value |
|---|---|---|
Max Particles |
Maximum number of particles to render for precipitation. |
0 to 1,000,000 |
Radius |
Radius over which to draw precipitation particles. |
0.0 to 100.0 m |
Rain Speed |
Speed of raindrops in meters per second (m/s). |
0.0 to 120.0 m/s |
Raindrop Size |
Size of raindrops in millimeters (mm). |
0.001 to 100.0 mm |
Snow Speed |
Speed of snowflakes in meters per second (m/s). |
0.0 to 120.0 m/s |
Snowflake Size |
Size of snowflakes in millimeters (mm). |
0.001 to 100.0 mm |
Wind Effect |
Strength of wind effect on rain or snow. |
0.0 to 1.0 |
Waver |
Strength of waver/sway of precipitation. Less noticeable for rain. |
0.0 to 1.0 |
Waver Time |
Timescale in seconds of precipitation waver. |
0 to 100 s |
Threshold |
Thickness of cloud required to produce precipitation in kilometers (km). |
0.0 to 10.0 km |
Virga Near Threshold |
The distance threshold for virga effects, also known as rain streaks. |
0 to 500km |
Unreal only¶
Variable |
Definition |
Value |
|---|---|---|
Rain Cubemap |
Cubemap to be used to light the Rain. |
Cubemap |
Velocity Streaks |
If the raindrop shape is altered by their velocity. |
Bool |
Simulation Time |
If time progression should be taken into account for rain fall. |
Bool |
Rain Near Threshold |
Draw no rain closer than this distance. |
0.01 to 0.5 |
Rain Mask Scene Capture 2D |
2D Screen capture to limit rain below surfaces. Learn more about this here. |
Scene Capture 2D |
Rain Mask Width |
Width of the Rain Mask. |
100 to 50000 |
Rain Mask Depth Extent |
Height of the Rain Mask. |
100 to 100000 |
Translucent RT |
The render texture used to render Precipitation effects. |
Render Texture |