| """ |
| I/O helpers for point clouds (PLY/PCD) and meshes (OBJ/PLY/GLB). |
| """ |
|
|
| from __future__ import annotations |
|
|
| from pathlib import Path |
| from typing import Optional, Tuple, Union |
|
|
| import numpy as np |
|
|
|
|
| def load_point_cloud( |
| path: Union[str, Path], |
| *, |
| estimate_normals: bool = False, |
| normal_knn: int = 30, |
| ) -> Tuple[np.ndarray, Optional[np.ndarray]]: |
| """ |
| Load a point cloud from a ``.ply`` or ``.pcd`` file. |
| |
| Parameters |
| ---------- |
| path : str or Path |
| Path to the input file. |
| estimate_normals : bool, default False |
| If the file does not contain normals, estimate them with Open3D. |
| normal_knn : int, default 30 |
| k-NN neighbourhood size for Open3D normal estimation. |
| |
| Returns |
| ------- |
| points : np.ndarray |
| (N, 3) float array of point positions. |
| normals : np.ndarray or None |
| (N, 3) float array of point normals, if available or estimated. |
| """ |
| path = Path(path) |
| suffix = path.suffix.lower() |
|
|
| if suffix in (".ply", ".pcd"): |
| points, normals = _load_with_open3d(path, estimate_normals, normal_knn) |
| else: |
| raise ValueError(f"Unsupported point-cloud format: {suffix}") |
|
|
| return points, normals |
|
|
|
|
| def _load_with_open3d( |
| path: Path, estimate_normals: bool, normal_knn: int |
| ) -> Tuple[np.ndarray, Optional[np.ndarray]]: |
| try: |
| import open3d as o3d |
| except ImportError as exc: |
| raise ImportError( |
| "open3d is required to load PLY/PCD files. " |
| "Install it with: pip install open3d" |
| ) from exc |
|
|
| pcd = o3d.io.read_point_cloud(str(path)) |
| points = np.asarray(pcd.points) |
|
|
| normals = None |
| if pcd.has_normals(): |
| normals = np.asarray(pcd.normals) |
| elif estimate_normals and len(points) > 0: |
| pcd.estimate_normals( |
| search_param=o3d.geometry.KDTreeSearchParamKNN(knn=normal_knn) |
| ) |
| pcd.orient_normals_consistent_tangent_plane(k=normal_knn) |
| normals = np.asarray(pcd.normals) |
|
|
| return points, normals |
|
|
|
|
| def save_mesh( |
| path: Union[str, Path], |
| vertices: np.ndarray, |
| faces: np.ndarray, |
| vertex_colors: Optional[np.ndarray] = None, |
| ) -> None: |
| """ |
| Save a triangle mesh to a file. |
| |
| Supported formats: ``.ply``, ``.obj``, ``.glb``, ``.stl``, ``.off`` |
| (anything Trimesh supports). |
| """ |
| import trimesh |
|
|
| path = Path(path) |
|
|
| |
| vertices = np.asarray(vertices, dtype=np.float32) |
| faces = np.asarray(faces, dtype=np.int32) |
|
|
| mesh = trimesh.Trimesh( |
| vertices=vertices, |
| faces=faces, |
| vertex_colors=vertex_colors, |
| ) |
| mesh.export(str(path)) |
|
|
