# NodeSlicer Agent Instructions

## Project Overview
NodeSlicer is a high-performance Blender extension providing a custom node-based interface for mesh slicing and G-code generation.

## Critical Context
- **Purpose**: 3D printing slicing, CNC toolpathing, and procedural geometry tasks
- **Main Technologies**: Python, Blender API (`bpy`), NumPy, Pyclipper, Shapely
- **Blender Version**: 4.2 or newer (required for the Extension platform)
- **Architecture**: Separates Blender-specific UI and data capture (`infra/`) from core geometric and slicing algorithms (`core/`)

## Development Conventions

### Registration
All Blender classes (Nodes, Sockets, Operators, Menus) must be decorated with `@register_class` from `registry.py` to ensure they are registered correctly during initialization.

### Node Evaluation
Nodes follow a pull-based evaluation model. Use `resolve_input(self.inputs.get("SocketName"))` within a node's `evaluate_output` method to trigger the evaluation of upstream nodes.

### Performance
For any geometry processing, prioritize NumPy vectorized operations over standard Python loops to maintain high performance.

### Scaling
2D polygon operations via Pyclipper use a `SCALE` factor (defined in `core/slice.py`) to convert floats to integers, as Pyclipper operates in integer space.

### Type Hinting
Use exhaustive type hints for all new functions and classes.

### Documentation
Update `doc/NODES.md` when adding new nodes and `doc/MODULES.md` when adding new modules.

## Project Structure
- `__init__.py`: Main entry point. Defines the `NodeSlicer Tree`, custom Sockets, and all Nodes.
- `registry.py`: Utility for automatic registration of Blender classes using the `@register_class` decorator.
- `core/slice.py`: Core slicing engine (plane-mesh intersection), buffering (offsetting), and infill generation.
- `core/geometry.py`: Shared geometry utility functions.
- `infra/blender_mesh_capture.py`: Logic for extracting mesh data from Blender objects into NumPy arrays.
- `infra/blender_slice_nodes_generic.py`: Base classes for the node system and the evaluation logic (`resolve_input`).
- `doc/`: Comprehensive documentation on modules and nodes.

## Commands
- Build the extension: `./build.sh` (generates a zip file in the `release/` directory)
- Install dependencies: `uv sync`

## Testing
- Tests are located in the `tests/` directory
- Run PDF exporter tests: `python -m unittest tests.test_pdf_exporter -v`
- Requires the virtual environment: `source .venv/bin/activate`