Blacksite/docs/editor/brushes.md

Brush Authoring

Brushes are persisted blockout geometry stored as ActorKind::Brush + BrushDesc.

MVP Scope

• BrushDesc::default() creates an additive cube brush.
• Each face stores a stable ID, plane, vertices, optional material/texture refs, UV offset/scale/rotation, and smoothing group.
• Hydration builds generated mesh children from active brush components and strips those children before scene save.
• Brush actors validate separately from primitives and imported/static mesh actors.
• The Actor Inspector Add Component shelf can add a Brush component. The Brush card exposes kind, face count, shadow flags, and cube reset.
• Draw Brush mode (B, toolbar pencil, or command brush.draw) creates additive prism brushes from snapped floor points. LMB places points, Backspace removes the last point, Enter commits through undo history, and Esc/right-click cancels without scene mutation.

Current Limits

• Only convex authored faces are supported by the mesh builder.
• Subtractive brushes are stored as markers but are not evaluated as CSG.
• Face, edge, vertex, clipping, and primitive brush creation tools are future roadmap work.