基于3D对象体积与直径特征的筛选

1，目的

• 筛选出目标3D对象。

  效果如下：
  

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2，原理

• 使用3D对象的体积与直径特征进行筛选。

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3，代码解析

3.1，预处理2.5D深度图。

* 参考案例库：select_object_model_3d.hdev
* ************************************************************
* 目的：
*     筛选所需要的3D模型
* 原理：
*     基于3D对象的体积与直径特征进行筛选* ************************************************************
* 
dev_update_off ()
dev_close_window ()
* Load X,Y,Z-Data, scale them to meter and generate a 3D object model
ImagePath := 'time_of_flight/'
* 加载2.5D深度图（带深度信息的图像）
read_image (Image, ImagePath + 'engine_cover_xyz_01')
* 将深度值(Z通道）缩小1000倍（实质是单位：mm->m）
scale_image (Image, Image, .001, .0)
* 长宽放大2倍用于增加细节观察
zoom_image_factor (Image, Image, 2, 2, 'constant')
decompose3 (Image, X, Y, Z)
xyz_to_object_model_3d (X, Y, Z, ObjectModel3DID)
* Compute a mesh (Delauney triangulation) of the model
prepare_object_model_3d (ObjectModel3DID, 'segmentation', 'true', [], [])

释疑解惑*

1，engine_cover_xyz-01.tif是什么图？

​ 2.5D图，是通过深度传感器（如结构光相机）获取的‌二维投影深度图‌。每个像素存储三维坐标值（X/Y/Z轴），非传统RGB或灰度数据，像素值以浮点型（real）存储物理空间位置，单位为毫米级精度。

2，zoom_image_factor 对效果的影响？

zoom_image_factor (Image, Image, 2, 2, 'constant')

显示效果：

zoom_image_factor (Image, Image, 1, 1, 'constant')

显示效果：

对比可知：长宽放大2倍可增加细节观察

3，prepare_object_model_3d算子的作用？

用于优化 3D 对象模型（点云或网格）的核心预处理算子，其主要功能是为后续三维视觉任务（如匹配、分割、测量）提供标准化输入。

1. 核心功能与技术细节

   • ‌数据规范化‌

     • 统一不同来源的 3D 数据格式（点云、网格模型等），修复拓扑缺陷（如孔洞填充、噪声过滤）。

     • ‌ 关键参数：

       • GenParamNames：指定预处理选项（如 'max_area_holes' 控制孔洞填充面积阈值）。
       • GenParamValues：设置参数值（如 'sampling' 调节点云采样密度）。

   • ‌几何特征计算‌

     • 自动生成法向量、曲率等几何属性，为基于形状的分割（segment_object_model_3d）或匹配（create_shape_model_3d）提供基础特征。

   • ‌多分辨率支持‌

     • 支持生成多层级细节模型（LOD），适应不同精度的处理需求，提升算法效率。

2. 工业检测流程

‌ 预处理后提升后续算法效率 20%+
例如：

1. 修复扫描点云的孔洞（'max_area_holes' 设为实际缺陷尺寸）。
2. 计算法向量辅助钣金件平面分割。

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3. 关键参数配置指南

‌参数‌	‌作用‌	‌典型值示例‌
Purpose	指定预处理目标： - 'shape_based_matching_3d'（匹配） - 'segmentation'（分割）	'segmentation'
GenParamNames	参数名数组： - 'point_coord_ranges'（坐标范围过滤） - 'distance_to'（邻近点距离）	['sampling','max_area_holes']
GenParamValues	对应参数值： - 采样密度 0.01（相对模型直径） - 最大孔洞面积 5.0（mm²）	[0.02, 10.0]

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4. 与其他算子的协同应用

   • ‌分割优化‌：预处理后输入 segment_object_model_3d，支持基于曲率/颜色的智能分割。

   • ‌距离计算‌：为 distance_object_model_3d 提供拓扑完整的模型，确保距离精度。

   • ‌位姿调整‌：配合 rigid_trans_object_model_3d 实现坐标变换前的数据规范化。

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5. 注意事项

   • ‌必要性‌：若不调用该算子，后续操作（如分割）可能因缺失拓扑信息而失败或低效。
   • ‌性能平衡‌：过高的采样密度（'sampling'）会增大内存开销，需根据任务需求权衡。

示例：轴承检测中，通过 prepare_object_model_3d 填充球体表面扫描缺失点，使 gen_sphere_object_model_3d 生成的参考模型与实际点云精确对齐212。

作用前:

作用后：

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3.2，去除背景，断开连接域

* Prepare the visualization and display the 3D object model
create_pose (0.058, -0.165, 0.660, 345.0, 355.0, 356.0, 'Rp+T', 'gba', 'point', Pose)
* 
* Instructions for visualize_object_model_3d
Instructions[0] := 'Rotate: Left button'
Instructions[1] := 'Zoom:   Shift + left button'
Instructions[2] := 'Move:   Ctrl  + left button'
* Configuration
CamParam := [0.01,0,7e-6,7e-6,352,288,710,576]
GenParamName := ['color','disp_pose','alpha','intensity']
GenParamValue := ['green','false',0.8,'none']
* 
dev_open_window (0, 0, 710, 576, 'black', WindowHandle)
set_display_font (WindowHandle, 16, 'mono', 'true', 'false')
* 
visualize_object_model_3d (WindowHandle, ObjectModel3DID, CamParam, Pose, GenParamName, GenParamValue, 'This scene will be segmented into single objects', [], Instructions, Pose)
* 
* Threshold the 3D object Model
MinValue := 0.500
MaxValue := 0.670
* 去除背景，筛选所需要的点云
select_points_object_model_3d (ObjectModel3DID, 'point_coord_z', MinValue, MaxValue, ObjectModel3DIDReduced)
visualize_object_model_3d (WindowHandle, ObjectModel3DIDReduced, CamParam, Pose, GenParamName, GenParamValue, 'Result after thresholding at z=' + (MaxValue * 1e3)$'.3' + 'mm from the camera', [], Instructions, Pose)
* 
* Calculate the connected components and the volume and diameter
* of each of the resulting object
GenParamName[0] := 'colored'
GenParamValue[0] := 12
* 断开连接域
connection_object_model_3d (ObjectModel3DIDReduced, 'distance_3d', 0.010, ObjectModel3DIDConnections)

ObjectModel3DIDConnections如图所示：

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3.3，计算特征量：体积与直径

* 计算3D对象的相对于平面的体积
volume_object_model_3d_relative_to_plane (ObjectModel3DIDConnections, [0,0,MaxValue,0,0,0,0], 'signed', 'true', Volume)
* 计算3D对象的最大直径
max_diameter_object_model_3d (ObjectModel3DIDConnections, Diameter)
* 
* Display the results
dev_open_window (0, 720, 400, 576, 'black', WindowHandle1)
set_display_font (WindowHandle1, 14, 'mono', 'true', 'false')
Indices := [0:|ObjectModel3DIDConnections| - 1]
disp_message (WindowHandle1, ['Features of the connected components:',' ',' '], 'window', 12, 12, 'white', 'false')
ResultMessage := '  #  Max. diameter    Volume'
Sequence := [0:|ObjectModel3DIDConnections| - 1]
ResultMessage := [ResultMessage,Sequence$' 3' + '     ' + (Diameter * 1e3)$'7.1f' + ' mm  ' + (Volume * 1e3)$'7.3f' + ' dm³']
disp_message (WindowHandle1, ResultMessage, 'window', 50, 12, 'white', 'false')
dev_set_window (WindowHandle)
visualize_object_model_3d (WindowHandle, ObjectModel3DIDConnections, CamParam, Pose, GenParamName, GenParamValue, 'Found ' + |ObjectModel3DIDConnections| + ' connected components', '#' + Indices, Instructions, Pose)

释疑解惑

1，volume_object_model_3d_relative_to_plane的作用？

volume_object_model_d_relative_to_plane(  : :  ObjectModel3D,       // 输入3D模型句柄  Plane,               // 参考平面位姿或平面方程  Mode,                // 体积计算模式  UseFaceOrientation   // 是否考虑面片方向  : Volume             // 输出体积值  
)

• 算子功能‌

计算3D对象模型相对于参考平面的体积分布，支持半空间体积分析和方向敏感计算。

• ‌参数详解‌

  1. ‌ObjectModel3D‌

     • ‌类型‌：输入对象

     • ‌要求‌：必须为三角化网格或包含多边形集合的3D模型。

     • ‌注意‌：若网格非封闭或面片不连续，计算结果受 Mode 和 UseFaceOrientation 参数影响。

  2. ‌Plane‌

     • ‌定义‌：标准平面方程参数 [a, b, c, d]，对应方程 ax + by + cz + d = 0。

     • ‌获取方式

       • 通过 fit_primitives_object_model_3d 拟合点云平面；
       • 手动定义（如 [0, 0, 1, -100] 表示 z=100 的平面）。

  3. Mode‌

控制体积计算模式，可选值及含义：

‌模式‌	‌计算逻辑‌	‌应用场景‌
'signed'	返回平面以上（正）和以下（负）体积的代数和（例：80 + (-40) = 40）	需要方向信息的平衡分析
'unsigned'	返回平面上下体积绝对值之和（例：`	80
'positive'	仅计算平面以上体积（正值）	凸起特征测量（如焊接高度）
'negative'	仅计算平面以下体积（自动取绝对值）	凹陷或容器液位分析

4. UseFaceOrientation‌

   • **'true'**‌：考虑三角面片的法向方向，精确判断面片与平面的相对位置（适用于CAD模型）。
   • ‌**'false'**‌：仅根据顶点位置判断面片在平面上/下（适用于点云数据）。

5. Volume‌

   • ‌输出‌：根据 Mode 返回对应的体积值（单位与模型坐标一致）。

• 工业应用示例‌

  1. ‌注塑件毛刺检测 ‌

     • 定义分型面平面，使用 'positive' 模式检测凸出异常体积。

  2. 容器液位测量

     • 设置液面平面，通过 'negative' 模式计算液体体积。

• ‌注意事项‌

  • ‌模型质量‌：网格法向一致性会影响方向敏感模式（UseFaceOrientation='true'）的结果精度19。

  • ‌性能优化‌：对非封闭模型，优先使用 'false' 模式以减少计算开销11。

Plane效果演示：

3.4，筛选出3D对象

* Select components by their volume and maximal diameter
* 
MinVolume := 0.35e-003
MaxVolume := 1.0e-003
MinDiameter := 185.0e-003
MaxDiameter := 300.0e-003
* *** Attention:
*     select_object_model_3d uses the plane [0,0,0,0,0,0]
*     for the volume calculation! Therefore we have
*     to transform the 3d object models, so that the
*     reference plane (as defined in the former call to
*     volume_object_model_3d_relative_to_plane) coincides to the
*     default plane.
hom_mat3d_identity (HomMat3DIdentity)
hom_mat3d_translate (HomMat3DIdentity, 0, 0, -MaxValue, HomMat3DTranslation)
hom_mat3d_invert (HomMat3DTranslation, HomMat3DInvert)
affine_trans_object_model_3d (ObjectModel3DIDConnections, HomMat3DTranslation, ObjectModel3DTranslated)
* Set a label for each part
for Index := 0 to |ObjectModel3DIDConnections| - 1 by 1set_object_model_3d_attrib_mod (ObjectModel3DTranslated[Index], '&Index', [], Index)
endfor
* 
volume_object_model_3d_relative_to_plane (ObjectModel3DTranslated, [0,0,0,0,0,0,0], 'signed', 'true', Volume1)
select_object_model_3d (ObjectModel3DTranslated, ['volume','diameter_object'], 'and', [MinVolume,MinDiameter], [MaxVolume,MaxDiameter], ObjectModel3DSelected)
* 
Title := ['Parts selected by using the following features: ','       ' + (MinVolume * 1e3)$'3.1f' + ' dm³ <= volume <= ' + (MaxVolume * 1e3)$'3.1f' + ' dm³','and:   ' + (MinDiameter * 1e3)$'.1f' + ' mm <= max. diameter <= ' + (MaxDiameter * 1e3)$'.1f' + ' mm']
* Create the labels
Label := []
for Index := 0 to |ObjectModel3DSelected| - 1 by 1get_object_model_3d_params (ObjectModel3DSelected[Index], '&Index', FormerIndex)Label := [Label,'#' + FormerIndex]
endfor
* 
if (|ObjectModel3DSelected| > 1)visualize_object_model_3d (WindowHandle, ObjectModel3DSelected, CamParam, [], GenParamName, GenParamValue, Title, Label, Instructions, Pose)
elseMessage := 'No object left after using the following features: 'Message[1] := '       ' + (MinVolume * 1e3)$'3.1f' + ' dm³ <= volume <= ' + (MaxVolume * 1e3)$'3.1f' + ' dm³'Message[2] := 'and:   ' + (MinDiameter * 1e3)$'.1f' + ' mm <= max. diameter <= ' + (MaxDiameter * 1e3)$'.1f' + ' mm'disp_message (WindowHandle, Message, 'window', 12, 12, 'black', 'true')
endif
* 
* Clear the 3d object models
dev_set_window (WindowHandle1)
dev_close_window ()
clear_object_model_3d ([ObjectModel3DID,ObjectModel3DIDReduced,ObjectModel3DSelected,ObjectModel3DTranslated,ObjectModel3DIDConnections])

筛选结果：

4，完整代码。

* 参考案例库：select_object_model_3d.hdev
* ************************************************************
* 目的：
*     筛选所需要的3D模型
* 原理：
*     基于3D对象的体积与直径特征进行筛选* ************************************************************
* 
dev_update_off ()
dev_close_window ()
* Load X,Y,Z-Data, scale them to meter and generate a 3D object model
ImagePath := 'time_of_flight/'
* 加载2.5D深度图（带深度信息的图像）
read_image (Image, ImagePath + 'engine_cover_xyz_01')
* 将深度值(Z通道）缩小1000倍（实质是单位：mm->m）
scale_image (Image, Image, .001, .0)
* 长宽放大2倍用于增加细节观察
zoom_image_factor (Image, Image, 2,2, 'constant')
decompose3 (Image, X, Y, Z)
xyz_to_object_model_3d (X, Y, Z, ObjectModel3DID)
* Compute a mesh (Delauney triangulation) of the model
prepare_object_model_3d (ObjectModel3DID, 'segmentation', 'true', [], [])
* 
* Prepare the visualization and display the 3D object model
create_pose (0.058, -0.165, 0.660, 345.0, 355.0, 356.0, 'Rp+T', 'gba', 'point', Pose)
* 
* Instructions for visualize_object_model_3d
Instructions[0] := 'Rotate: Left button'
Instructions[1] := 'Zoom:   Shift + left button'
Instructions[2] := 'Move:   Ctrl  + left button'
* Configuration
CamParam := [0.01,0,7e-6,7e-6,352,288,710,576]
GenParamName := ['color','disp_pose','alpha','intensity']
GenParamValue := ['green','false',0.8,'none']
* 
dev_open_window (0, 0, 710, 576, 'black', WindowHandle)
set_display_font (WindowHandle, 16, 'mono', 'true', 'false')
* 
visualize_object_model_3d (WindowHandle, ObjectModel3DID, CamParam, Pose, GenParamName, GenParamValue, 'This scene will be segmented into single objects', [], Instructions, Pose)
* 
* Threshold the 3D object Model
MinValue := 0.500
MaxValue := 0.670
* 去除背景，筛选所需要的点云
select_points_object_model_3d (ObjectModel3DID, 'point_coord_z', MinValue, MaxValue, ObjectModel3DIDReduced)
visualize_object_model_3d (WindowHandle, ObjectModel3DIDReduced, CamParam, Pose, GenParamName, GenParamValue, 'Result after thresholding at z=' + (MaxValue * 1e3)$'.3' + 'mm from the camera', [], Instructions, Pose)
* 
* Calculate the connected components and the volume and diameter
* of each of the resulting object
GenParamName[0] := 'colored'
GenParamValue[0] := 12
* 断开连接域
connection_object_model_3d (ObjectModel3DIDReduced, 'distance_3d', 0.010, ObjectModel3DIDConnections)
* gen_plane_object_model_3d ([0,0,MaxValue,0,0,0,0], [-0.5,-0.5,0.5,0.5], [0.5,-0.5,-0.5,0.5],plane01)* visualize_object_model_3d (WindowHandle, [plane01,ObjectModel3DIDConnections], [], [],\['color_0','color_'+[1:|ObjectModel3DIDConnections|-1],'alpha_0','disp_pose'], ['orange',gen_tuple_const(|ObjectModel3DIDConnections|-1,'green')  ,0.7,'true'], [], [], [], PoseOut)
* 计算3D对象的相对于平面的体积
volume_object_model_3d_relative_to_plane (ObjectModel3DIDConnections, [0,0,MaxValue,0,0,0,0], 'negative', 'true', Volume)
* 计算3D对象的最大直径
max_diameter_object_model_3d (ObjectModel3DIDConnections, Diameter)
* 
* Display the results
dev_open_window (0, 720, 400, 576, 'black', WindowHandle1)
set_display_font (WindowHandle1, 14, 'mono', 'true', 'false')
Indices := [0:|ObjectModel3DIDConnections| - 1]
disp_message (WindowHandle1, ['Features of the connected components:',' ',' '], 'window', 12, 12, 'white', 'false')
ResultMessage := '  #  Max. diameter    Volume'
Sequence := [0:|ObjectModel3DIDConnections| - 1]
ResultMessage := [ResultMessage,Sequence$' 3' + '     ' + (Diameter * 1e3)$'7.1f' + ' mm  ' + (Volume * 1e3)$'7.3f' + ' dm³']
disp_message (WindowHandle1, ResultMessage, 'window', 50, 12, 'white', 'false')
dev_set_window (WindowHandle)
visualize_object_model_3d (WindowHandle, ObjectModel3DIDConnections, CamParam, Pose, GenParamName, GenParamValue, 'Found ' + |ObjectModel3DIDConnections| + ' connected components', '#' + Indices, Instructions, Pose)
* 
* Select components by their volume and maximal diameter
* 
MinVolume := 0.35e-003
MaxVolume := 1.0e-003
MinDiameter := 185.0e-003
MaxDiameter := 300.0e-003
* *** Attention:
*     select_object_model_3d uses the plane [0,0,0,0,0,0]
*     for the volume calculation! Therefore we have
*     to transform the 3d object models, so that the
*     reference plane (as defined in the former call to
*     volume_object_model_3d_relative_to_plane) coincides to the
*     default plane.
hom_mat3d_identity (HomMat3DIdentity)
hom_mat3d_translate (HomMat3DIdentity, 0, 0, -MaxValue, HomMat3DTranslation)
hom_mat3d_invert (HomMat3DTranslation, HomMat3DInvert)
affine_trans_object_model_3d (ObjectModel3DIDConnections, HomMat3DTranslation, ObjectModel3DTranslated)
* Set a label for each part
for Index := 0 to |ObjectModel3DIDConnections| - 1 by 1set_object_model_3d_attrib_mod (ObjectModel3DTranslated[Index], '&Index', [], Index)
endfor
* 
volume_object_model_3d_relative_to_plane (ObjectModel3DTranslated, [0,0,0,0,0,0,0], 'signed', 'true', Volume1)
select_object_model_3d (ObjectModel3DTranslated, ['volume','diameter_object'], 'and', [MinVolume,MinDiameter], [MaxVolume,MaxDiameter], ObjectModel3DSelected)
* 
Title := ['Parts selected by using the following features: ','       ' + (MinVolume * 1e3)$'3.1f' + ' dm³ <= volume <= ' + (MaxVolume * 1e3)$'3.1f' + ' dm³','and:   ' + (MinDiameter * 1e3)$'.1f' + ' mm <= max. diameter <= ' + (MaxDiameter * 1e3)$'.1f' + ' mm']
* Create the labels
Label := []
for Index := 0 to |ObjectModel3DSelected| - 1 by 1get_object_model_3d_params (ObjectModel3DSelected[Index], '&Index', FormerIndex)Label := [Label,'#' + FormerIndex]
endfor
* 
if (|ObjectModel3DSelected| > 1)visualize_object_model_3d (WindowHandle, ObjectModel3DSelected, CamParam, [], GenParamName, GenParamValue, Title, Label, Instructions, Pose)
elseMessage := 'No object left after using the following features: 'Message[1] := '       ' + (MinVolume * 1e3)$'3.1f' + ' dm³ <= volume <= ' + (MaxVolume * 1e3)$'3.1f' + ' dm³'Message[2] := 'and:   ' + (MinDiameter * 1e3)$'.1f' + ' mm <= max. diameter <= ' + (MaxDiameter * 1e3)$'.1f' + ' mm'disp_message (WindowHandle, Message, 'window', 12, 12, 'black', 'true')
endif
* 
* Clear the 3d object models
dev_set_window (WindowHandle1)
dev_close_window ()
clear_object_model_3d ([ObjectModel3DID,ObjectModel3DIDReduced,ObjectModel3DSelected,ObjectModel3DTranslated,ObjectModel3DIDConnections])