RegionShell

The surface of one region's field, as RegionLayer draws it (construct-project-space §PSR-2: "they render in the viewport as ordinary translucent volumes").

In the namespace construct::asset. Declared in src/libs/libconstruct/construct/asset/RegionShell.hpp.

Detailed description

The field is cut to the box of the tet volumes it can select on, so the shell is closed and shows where the region acts. The vertices are in the region item's own frame: the layer places them with the item's current world matrix, so a drag of the gizmo moves the shell at once, and only a change of the field or of the volumes builds a new one.

Built on the thread pool with the live count (RegionLiveCount), never on a render thread. Immutable once built: a new shell is a new object, so a consumer detects a change by pointer.