Material ID renders a colour ID pass from your 3D model. Every surface in the model becomes its own selectable region, so you can restyle surfaces by picking them rather than describing them.
Why it is more precise than a prompt
The ID pass already encodes exactly which pixels belong to which surface, so the regions are exact rather than traced by eye. They are also stable between re-renders, which is the part that matters in practice: changing one material leaves everything else pixel-identical instead of subtly redrawing the whole image.
Using it
- Open a model first: the pass is rendered from model geometry, not from a flat image
- Render the Material ID pass, then open it in Edit
- Pick a surface from the list and assign a material to it
- Dismiss any surface row you do not intend to change, to keep the list short
When to reach for something else
Material ID needs a linked 3D model. For a one-off change to part of an image you already have, a Smart Note is quicker.