Weather parameters
Each biome and base layer in the Material Instance has a Weather category with the same parameter set. Per-material weather is what lets a Tropical Rainforest run drenched while a neighbouring Desert stays dry. Background on the system is in the weather system concept.
Per-layer toggles and intensity
Section titled “Per-layer toggles and intensity”| Parameter | Effect |
|---|---|
bEnableBiomeXWeather or bEnableBaseXWeather | Master toggle for this layer’s weather response. Located in the Weather section of the Material Instance, where X is the biome or base name. |
Biome_X_R_PSt or Base_X_R_PSt | Rain intensity for this layer. Configured in MPC_Weathers. |
Biome_X_S_PSt or Base_X_S_PSt | Snow intensity for this layer. Configured in MPC_Weathers. |
X is the layer name. Biomes: Tundra, BorealForest, Desert, Mediterranean, Savanna, TemperateForest, TropicalRainforest, Wetland, Grassland, Custom1, Custom2, Custom3. Base layers: Beach, Cliff, Grass, Gravel, Mud, Snow.
Wet surface tuning
Section titled “Wet surface tuning”When a layer’s weather is enabled, the following parameters control how the wet look reads on screen.
Wave surface (puddles and standing water)
Section titled “Wave surface (puddles and standing water)”| Parameter | Effect |
|---|---|
WaveUVScale | Scale of the rippling water wave surface. |
WaveNormalIntensity | Normal intensity of the wave surface. |
WaveUVSpeed | Animation speed of the wave UV. |
Rain ripples
Section titled “Rain ripples”| Parameter | Effect |
|---|---|
RippleStrength | Strength of raindrop ripples on the water surface. |
RippleScale | Scale of the rain-ripple pattern. |
RippleSpeed | Speed of the ripple animation. |
Puddle masks
Section titled “Puddle masks”| Parameter | Effect |
|---|---|
WaterPuddleTilling | Tiling for the water puddle mask. |
RainMudPuddleTilling | Tiling for the rain mud puddle mask. |
SnowPuddleTilling | Tiling for the snow puddle mask. |
SnowMudPuddleTilling | Tiling for the snow mud puddle mask. |
The split across water puddle, rain mud puddle, snow puddle, and snow mud puddle gives you separate art-direction control over each kind of wet surface.
Where to next
Section titled “Where to next”- Weather system concept: the design rationale
- Special parameters: includes puddle strength controls that interact with weather
- Season parameters: the parallel system for color shifts