nodeslicer/doc

NodeSlicer Technical Overview

NodeSlicer is a Blender extension designed for high-performance mesh slicing and G-code generation. It provides a node-based interface that abstracts away the complexity of 3D-to-2D geometry conversion, offering a pipeline for 3D printing workflows.

Core Principles

1. Fast Slicing: Bypasses the Blender CPU-bound Boolean modifiers by using vectorized plane-triangle intersection via NumPy.
2. Robust Geometry: Leverages Shapely (built on GEOS) for all 2D operations, ensuring topological correctness in offset/buffering and boundary extraction.
3. Extensibility: A custom Node Tree architecture allows for easy creation of new nodes for custom toolpath strategies or post-processing.
4. Blender Integration: Deeply integrated into Blender's UI while maintaining a decoupled geometry engine for maximum performance.

System Architecture

graph TD
    UI[Blender Node Editor] --> Eval[Node Evaluation Engine]
    Eval --> Capture[Mesh Capture - infra/blender_mesh_capture]
    Capture --> Slice[Slicing Logic - core/slice]
    Slice --> Gcode[G-code Generation - core/slice]
    Gcode --> Export[File Export]

Data Lifecycle

• Mesh Data: Extracted from Blender as (N, 4, 3) NumPy arrays representing triangles and face normals.
• 2D Contours (Slices): Stored as a list of closed paths (NumPy arrays). Coordinates include Z-height. Topology (shells/holes) is managed via Pyclipper using the Even-Odd fill rule.
• Toolpaths (Paths): Stored as a list of open or closed paths (NumPy arrays). These represent the actual motion lines of the 3D printer.
• G-code: Formatted strings that include travel moves (G0), extrusions (G1), and metadata (layer change comments).

Important Files

• __init__.py: Node tree and evaluation engine definition.
• core/slice.py: Slicing and G-code generation algorithms.
• infra/blender_mesh_capture.py: High-performance mesh extraction from Blender.
• registry.py: Central registration of Blender classes.