Spectral Subsurface Boost
Spectral Subsurface Boost adjusts the subsurface color used during baking while leaving the runtime color unchanged. Its main use is controlling how much light passes through thin foliage during the bake without changing the leaves' normal in-game appearance.
Use it with Two Sided Foliage, or a Subsurface material with Two Sided enabled, on the supported non-Substrate bake path. It does not select that shading model or configure the material for you.
Inputs and output
| Connection | Type | Purpose |
|---|---|---|
| Subsurface Color input | Required RGB | The original color to preserve at runtime and adjust for baking. |
| Boost input | Optional scalar | Overrides the node's Bake Boost property. Useful for a scalar parameter controlled by material instances. |
| Output | RGB | Original color at runtime; boosted, bounded color during the bake. Connect to the material's Subsurface Color input. |
A missing Subsurface Color input produces a material compilation error. Connecting Boost does not replace the required color input.
Bake Boost
Default: 2. Minimum: 0. The editor slider extends to 4, but 4 is not a hard maximum.
This property is used only when the Boost pin is unconnected. A connected scalar takes precedence, so changing the property will not change the result in that case.
- 0: removes this bake-side subsurface contribution.
- 1: preserves the original color for the bake.
- Above 1: increases the bake-side color until its channels reach their limit.
Negative boost values are treated as 0. The resulting baked color is clamped to the 0 to 1 range per channel. For example, a channel at 0.4 becomes 0.8 with boost 2, but a channel at 0.8 becomes 1, not 1.6. Once a channel reaches 1, increasing the boost cannot brighten it further.
Example: light passing through leaves
Place the node between the existing subsurface color source and the material output:
Leaf subsurface color → Spectral Subsurface Boost → Subsurface Color
Start with boost 1 to compare against the unmodified bake, then try a moderate increase if the baked transmission through the leaves is too weak. Keep the runtime foliage setup unchanged while comparing bakes.
This node changes the bake's subsurface response. It does not make the leaf emit its own light, and it is not a replacement for Emissive Boost.
When to rebake
Apply and save the material, then rebake after changing the color or effective boost. The ordinary runtime viewport intentionally keeps the original color, so a lack of immediate runtime change is expected.
If the bake still does not change, check the shading model, Two Sided setting, input connections, and whether the color channels are already clamped. Increasing the multiplier indefinitely is not a way around that clamp.