# ifc-geometry surface instructions
Scope: Borrowed views and local semantic validation for IFC surface entities.
Follow the crate `../../AGENTS.md`.
## Owns
- elementary/swept/bounded/B-spline surface views
- surface parameterization and boundaries
- surface-specific rules
## Does not own
- surface meshing
- surface intersection algorithms
- B-rep topology ownership
## Growth map
`elementary.rs`, `swept.rs`, `bounded.rs`, `bspline.rs`. These source owners already compile as private scaffold modules. Replace a module's planned-owner marker with its first real contract and tests; do not add parallel placeholders.
Every source entity error cites EntityId/type/slot or rule. Add invalid, cycle,
and unsupported cases, not only happy paths.