Shortcut: O Key

Feather selection: CTRL + LMB drag from control point

When drawing a Bezier roto in Viewer, hold CTRL and use LMB to draw in freehand mode.

Note that freehand mode can generate a significant number of control points, so use them strategically. Use this conservatively when considering animated rotos, though it can be quite effective for static rotos.

Set the Merge operation to Max to verify that alpha values do not go over 1.0.

Use a Copy node to inject Roto mask into B-pipe, then set Viewer to the Copy node and use M key in Viewer to visualize mask over original plate.

The default is set to format, but verify the plate that the roto is being applied to. If the plate has a different format than the project format, then this property may need to be set to bbox so as not to distort the generated mask.