Region

An optional soft-edged circular boundary any Insert FX slot can turn on, independent of which effect the slot runs. Two or more slots with Region on fuse together at their edges when their circles come close.

Parameter	Control	Range	Notes
Enable Region	Rocker		Off by default. Outside this slot’s boundary the chain’s normal image continues untouched; the effect only shows inside the circle.
Center X / Center Y	Pad	-0.5 to 0.5
Radius	Trough	0 to 1.5
Feather	Trough	0 to 0.5	Softness of the circle’s edge.
Fusion	Trough	0.001 to 0.5	How eagerly this slot’s circle merges into a nearby Region’d slot’s circle. Low values hold a hard seam even at close range; high values bulge and merge from farther away.

NOTE: with two or more Region’d slots active in one chain, they always merge as a single group at the stacking position of the lowest-numbered slot among them. A slot without Region can’t sit between two merging Region’d slots in the chain’s stacking order.

NOTE: an empty slot (effect type NONE) has no Region controls to show.

Related: Mask, which uses the same circular edge-and-feather boundary for a single slot’s own coverage. Insert FX Chains.