Expands or resets an image’s bounding box by a pixel amount, then copies that bbox onto the original input for overscan and downstream padding.
Fill BBox is a utility group that builds a new bounding box and applies it to your plate without changing the underlying RGB(A) through a conventional composite. The input is cropped to format, widened with AdjBBox, and the resulting bounds are transferred back with CopyBBox.
Use it when a tight data window clips blurs, warps, merges, or edge work. Add Pixels controls how many pixels AdjBBox grows the box; set bbox to chooses the Merge bbox mode that defines those bounds before CopyBBox.
In a comp it sits inline as a padding step: same image content, larger or retargeted bbox, so nodes that respect the data window get the overscan they need.