Convex Hull
Convex Hull creates a surface that envelopes the selected geometries, e.g. a bubble that encloses all selected surfaces/lines/points. This can be used to recreate simplified slopes or ore bodies that were stored as unstructured triangle soups. In short, this option allows to create a volume and assign it as the material extents.
To use convex hull, select: Geometry > Surface Triangulation Tools > Convex Hull.
Below is an example from RS3 of where convex hull can be applied:

Select all entities and use Convex Hull and it creates an envelope surrounding the original ore body:
