blender_render.py

import bpy
import sys
import argparse
from math import radians
from mathutils import Vector

# 解析命令行参数
argv = sys.argv[sys.argv.index("--") + 1:]
parser = argparse.ArgumentParser()
parser.add_argument("--input", required=True, help="Path to .glb file")
parser.add_argument("--output", required=True, help="Path to output .png image")
args = parser.parse_args(argv)

# 清理默认场景
bpy.ops.object.select_all(action='SELECT')
bpy.ops.object.delete(use_global=False)

# 导入 GLB 模型
bpy.ops.import_scene.gltf(filepath=args.input)

# 缩放模型（KiCad 导出是 mm，Blender 默认单位是 m）
for obj in bpy.context.scene.objects:
    obj.scale = (1000, 1000, 1000)

scene = bpy.context.scene

# 创建相机
cam_data = bpy.data.cameras.new("Camera")
cam_obj = bpy.data.objects.new("Camera", cam_data)
scene.collection.objects.link(cam_obj)
scene.camera = cam_obj

# 获取所有 MESH 对象的边界框中心和尺寸
mesh_objs = [obj for obj in scene.objects if obj.type == 'MESH']
if not mesh_objs:
    print("❌ No mesh objects found.")
    sys.exit(1)

min_corner = Vector((float('inf'), float('inf'), float('inf')))
max_corner = Vector((float('-inf'), float('-inf'), float('-inf')))
for obj in mesh_objs:
    for v in obj.bound_box:
        world_v = obj.matrix_world @ Vector(v)
        min_corner = Vector(map(min, min_corner, world_v))
        max_corner = Vector(map(max, max_corner, world_v))

center = (min_corner + max_corner) / 2
size = max_corner - min_corner
distance = max(size.x, size.y) * 1.5

# 设置相机位置和角度（俯视角度）
cam_obj.location = (center.x, center.y, center.z + distance)
cam_obj.rotation_euler = (radians(90), 0, 0)

# 添加光照（太阳光）
light_data = bpy.data.lights.new(name="Sun", type='SUN')
light_obj = bpy.data.objects.new(name="Sun", object_data=light_data)
scene.collection.objects.link(light_obj)
light_obj.location = (center.x, center.y, center.z + distance * 2)
light_obj.rotation_euler = (radians(90), 0, 0)

# 设置渲染参数
scene.render.engine = 'CYCLES'
scene.render.resolution_x = 1024
scene.render.resolution_y = 768
scene.render.filepath = args.output

# 使用 GPU 渲染（如果支持）
prefs = bpy.context.preferences
cprefs = prefs.addons['cycles'].preferences
cprefs.compute_device_type = 'CUDA'  # 或 'OPTIX' / 'OPENCL' / 'NONE'
scene.cycles.device = 'GPU'

# 渲染并保存图像
bpy.ops.render.render(write_still=True)