!!! info ""
FlattenLayerSet provides a simple way to merge additive [LayerSets](core.md#layersets)
from multichannel cg render passes to any single layer
| knob name | type | what it does |
|---|---|---|
| operation | enumeration | decides which method combination to use |
| layer_set | enumeration | decides which LayerSet to use |
| target_layer | enumeration | selects which layer to pre-subtract layers from (if enabled) and add the modified layers to |
| math mode | what it does |
|---|---|
| copy | replaces the target layer with the additive combination of the LayerSet |
| add | add the additive combination of the LayerSet to the target layer |
| remove | subtract the additive combination of the LayerSet from the target layer |