Stale wand selections

A pixel selection is baked from the image you clicked. The wand remembers its clicks and a fingerprint of that image. After a compositor edit, a frame change, a render, an undo or a file load, it re-reads the image once the compositor settles. If the pixels changed, the panel says so and offers Re-evaluate, which redoes the same clicks with the same settings on the new pixels.

• Clicks are stored as fractions of the image, so they land correctly after a resolution change.
• Auto Re-evaluate replays the clicks by itself whenever a change is found. It works from what the Image Editor shows, so it can't refresh during an animation render. For a selection that must follow a moving plate, use a live Color Range or Select Object selection.
• Brush strokes, Load, Selection from Node Output and Clear can't be replayed, so Re-evaluate is greyed out after them. To keep such a selection editable, turn it into shapes with Pixels to Shapes.