Grid and Branching

Grid support logic ensures deterministic trunk ownership and efficient branch reuse.

Grid placement policy

1. Resolve candidate to preferred snapped grid node.
2. If same-node trunk exists, join that tree.
3. Compare contact heights for trunk replacement vs new branch behavior.
4. Search alternate nodes only when no same-node trunk ownership applies.

Branch support contract

• Branches attach to host shafts instead of the build plate.
• Branches may chain recursively from trunk to branch to branch.
• Branch joints must be reprojected whenever parent shaft geometry changes.

Trunk replacement contract

• When a new candidate at the same node is higher than the current trunk contact, trunk replacement should be planned and applied as one coherent action.
• Dependents should be rehosted before the old trunk is removed.
• Undo and redo should treat the replacement as a single history event.

Known risk areas

• Front-most vs nearest snapping ambiguity in dense overlap scenes
• Segment ID collisions causing incorrect preview endpoint resolution
• Joint snapping instability under rapid topology edits

Related

• Support System
• Architecture and Handoff
• Support Placement

Reference issues are tracked in historical docs and issue tracker; keep this page focused on invariant behavior.