moldgen-3d-mesh

name	moldgen-3d-mesh
description	Work with 3D mesh processing in MoldGen. Use when implementing geometry algorithms, mesh operations, mold building, orientation analysis, parting surfaces, or GPU kernels.

MoldGen 3D Mesh Processing

Core Libraries

• trimesh: Primary mesh representation. trimesh.Trimesh for vertices/faces.
• manifold3d: Fast boolean operations (union, difference, intersection).
• scipy.spatial: KD-trees, convex hull, spatial transforms.
• scikit-image: Marching cubes for SDF→mesh conversion.
• numpy: All geometry math operates on numpy arrays.
• numba: CUDA JIT for GPU-accelerated voxelization and ray casting.

Key Modules

moldgen/core/
├── mesh_io.py           # Load/save (STL, OBJ, PLY, FBX, STEP, 3MF)
├── mesh_repair.py       # Hole filling, normal fixing, degenerate removal
├── mesh_editor.py       # Boolean ops, transform, simplify, subdivide
├── mesh_data.py         # MeshData dataclass, quality metrics
├── orientation.py       # Fibonacci sampling, undercut scoring, GPU ray casting
├── parting.py           # Parting line/surface generation
├── mold_builder.py      # Shell construction, alignment pins, bolt holes
├── gating.py            # Pour hole, vent placement
├── insert_generator.py  # Support plate: cross-section, conformal, anchor patterns
├── flow_sim.py          # L1 heuristic + L2 Darcy flow simulation
├── fea.py               # Finite element analysis
├── material.py          # Material database (silicone, PU, epoxy)
└── optimizer.py         # Gate position and parameter optimization

moldgen/gpu/
├── device.py            # GPU detection (CUDA, Numba, CuPy)
├── sdf.py               # SDF voxelization (numba CUDA)
├── ray_cast.py          # GPU ray casting for orientation
├── flow_kernel.py       # GPU Darcy flow solver
└── fallback.py          # CPU fallback implementations

Patterns

• Functions take trimesh.Trimesh or numpy arrays as input
• Return structured results (dataclasses or dicts)
• GPU functions check GPUDevice().info.available and fall back to CPU
• Voxel grids: numpy 3D arrays, resolution typically 64-256
• Coordinate system: Z-up, millimeters
• Mesh quality: always check watertight before boolean operations