geMoldInsight/src/core/mesh_generator.py

# src/core/mesh_generator.py
import logging
import numpy as np
from typing import Dict, List, Optional, Any
import trimesh
from OCC.Core.BRepMesh import BRepMesh_IncrementalMesh
from OCC.Core.TopExp import TopExp_Explorer
from OCC.Core.TopAbs import TopAbs_FACE
from OCC.Core.BRep import BRep_Tool
from OCC.Core.gp import gp_Pnt, gp_Vec
from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakeFace, BRepBuilderAPI_MakeEdge

logger = logging.getLogger(__name__)


class MeshGenerator:
    """网格生成器 - 从PythonOCC形状生成点云"""

    def __init__(self, quality: str = "medium"):
        self.quality_settings = {
            "low": 1.0,
            "medium": 0.5,
            "high": 0.1
        }
        self.quality = self.quality_settings.get(quality, 0.5)

    def generate_mesh_from_shape(self, shape, num_points: int = 50000) -> Dict:
        """从PythonOCC形状生成点云数据"""
        try:
            # 生成网格
            mesh = BRepMesh_IncrementalMesh(shape, self.quality)
            mesh.Perform()
            logger.info(f"OCC网格生成完成， 网格状态: {mesh.IsDone()}")
            
            # 提取三角形面数据
            vertices = []
            faces = []
            vertex_map = {}
            vertex_index = 0
            
            # 遍历所有面
            explorer = TopExp_Explorer(shape, TopAbs_FACE)
            while explorer.More():
                face = explorer.Current()
                
                # 获取面的三角形剖分
                face_triangulation = BRep_Tool.Triangulation(face)
                
                for i in range(1, face_triangulation.NbTriangles() + 1):
                    # 获取三角形的三个顶点
                    tri = face_triangulation.Triangle(i)
                    
                    # 获取顶点坐标
                    v1 = BRep_Tool.Pnt(face_triangulation, tri.Value(1) + 1)
                    v2 = BRep_Tool.Pnt(face_triangulation, tri.Value(2) + 1)
                    v3 = BRep_Tool.Pnt(face_triangulation, tri.Value(3) + 1)
                    
                    # 转换为坐标
                    p1 = (v1.X(), v1.Y(), v1.Z())
                    p2 = (v2.X(), v2.Y(), v2.Z())
                    p3 = (v3.X(), v3.Y(), v3.Z())
                    
                    # 添加顶点并获取索引
                    def add_vertex(p):
                        nonlocal vertex_index
                        key = (round(p[0], 6), round(p[1], 6), round(p[2], 6))
                        if key not in vertex_map:
                            vertex_map[key] = vertex_index
                            vertices.append(p)
                            vertex_index += 1
                        return vertex_map[key]
                    
                    idx1 = add_vertex(p1)
                    idx2 = add_vertex(p2)
                    idx3 = add_vertex(p3)
                    
                    faces.append([idx1 - 1, idx2 - 1, idx3 - 1])
            
            vertices = np.array(vertices, dtype=np.float32)
            faces = np.array(faces, dtype=np.int32)
            
            logger.info(f"提取了 {len(vertices)} 个顶点, {len(faces)} 个三角形面")
            
            # 创建Trimesh对象
            tri_mesh = trimesh.Trimesh(vertices=vertices, faces=faces)
            
            # 在网格表面采样点云
            points, face_idx = trimesh.sample.sample_surface(tri_mesh, num_points)
            
            # 获取法向量
            normals = tri_mesh.face_normals[face_idx]
            
            logger.info(f"生成了 {len(points)} 个点云点")
            
            return {
                "vertices": vertices.tolist(),
                "faces": faces.tolist(),
                "points": points.tolist(),
                "normals": normals.tolist(),
                "point_count": len(points),
                "vertex_count": len(vertices),
                "face_count": len(faces)
            }
            
        except Exception as e:
            logger.error(f"网格生成失败: {e}")
            import traceback
            logger.error(traceback.format_exc())
            # 返回示例数据
            return self._create_sample_pointcloud()

    def _create_sample_pointcloud(self) -> Dict:
        """创建示例点云（备用）"""
        # 创建一个简单的立方体点云
        mesh = trimesh.creation.box([100, 80, 50])
        points, _ = trimesh.sample.sample_surface(mesh, 5000)
        normals = mesh.face_normals
        
        return {
            "vertices": mesh.vertices.tolist(),
            "faces": mesh.faces.tolist(),
            "points": points.tolist(),
            "normals": normals.tolist(),
            "point_count": len(points),
            "vertex_count": len(mesh.vertices),
            "face_count": len(mesh.faces)
        }