https://player.vimeo.com/video/643517911?h=e4c8b05a58&badge=0&autopause=0&player_id=0&app_id=58479
mtSelect using a Noise shader selection on a Sphere.
You can use a vertex map or selection tags to define where selections are generated.
Drag the tag from the Object Manager into the Selection Map link field.
The Plane on the left has a polygon selection tag, which is displayed in the viewport. An identical Plane is on the right, as a child of a mtSelect, driving the selection generation.
The Plane on the left has a vertex map, which is displayed in the viewport. An identical Plane is on the right, as a child of a mtSelect. The vertex weights are driving the selection generation.