code/cube3d/render/render_obj4view.py

import os
import pymeshlab as ml

input_dir = "/public/home/wangshuo/gap/assembly/data/car_1k/obj"
output_base_dir = "/public/home/wangshuo/gap/assembly/data/car_1k/pose_4view"

import os
import pymeshlab as ml
import numpy as np


# 四个视角的旋转角度
rotations = [
    {"x": -90, "y": 0},
    {"x": -90, "y": 90},
    {"x": -90, "y": 180},
    {"x": -90, "y": 270},
]

# 旋转矩阵计算函数
def get_rotation_matrix(x_angle, y_angle):
    # 计算绕 x 轴的旋转矩阵
    x_rot_matrix = np.array([
        [1, 0, 0],
        [0, np.cos(np.radians(x_angle)), -np.sin(np.radians(x_angle))],
        [0, np.sin(np.radians(x_angle)), np.cos(np.radians(x_angle))]
    ])
    
    # 计算绕 y 轴的旋转矩阵
    y_rot_matrix = np.array([
        [np.cos(np.radians(y_angle)), 0, np.sin(np.radians(y_angle))],
        [0, 1, 0],
        [-np.sin(np.radians(y_angle)), 0, np.cos(np.radians(y_angle))]
    ])
    
    # 合成旋转矩阵（先绕 x 轴旋转，再绕 y 轴旋转）
    rotation_matrix = np.dot(y_rot_matrix, x_rot_matrix)
    
    return rotation_matrix

# 遍历每个 obj 文件
for filename in os.listdir(input_dir):
    if filename.endswith(".obj"):
        obj_path = os.path.join(input_dir, filename)
        base_name = os.path.splitext(filename)[0]

        # 创建渲染输出目录
        for i, rotation in enumerate(rotations):
            output_dir = os.path.join(output_base_dir, f"view_{i+1}")
            os.makedirs(output_dir, exist_ok=True)

            # 加载网格
            ms = ml.MeshSet()
            ms.load_new_mesh(obj_path)

            # 获取旋转矩阵
            rot_matrix = get_rotation_matrix(rotation["x"], rotation["y"])

            # 应用旋转矩阵
            ms.apply_filter("transform_apply", matrix=rot_matrix.flatten().tolist())

            # 渲染并保存图片
            output_image_path = os.path.join(output_dir, f"{base_name}.png")
            ms.save_current_mesh_image(output_image_path, image_width=800, image_height=600)

            print(f"Rendered {filename} at rotation x={rotation['x']}°, y={rotation['y']}° -> {output_image_path}")

print("All OBJ files rendered.")