求截面面积(vtk)-1

vtk连点成面, 并求该截面的面积

缘起

试图通过求椎管最大横径确定穿刺轴线,由于椎管的截面的变异等原因导致截取的椎管不规则所以失败了…(见vtk的截面多边形裁切和质心的探索实验之三：求当前截面椎管的质心)
开始尝试直接求椎弓根截面面积…

探索过程

1. 连点成面

    def CreatePolygon(self, points):
        "Create a 3D plane from Nx3 numpy array"
        self.verts = vtk.vtkPoints()
        polygon = vtk.vtkPolygon()


        polygon_pid = polygon.GetPointIds()
        for i, p in enumerate(points):
            self.verts.InsertNextPoint(*tuple(p))
            polygon_pid.InsertNextId(i)


        polygon_cell = vtk.vtkCellArray()
        polygon_cell.InsertNextCell(polygon)


        self.pd = vtk.vtkPolyData()
        self.pd.SetPoints(self.verts)
        self.pd.SetPolys(polygon_cell)


        self.mapper = vtk.vtkPolyDataMapper()
        self.mapper.SetInputData(self.pd)
        self.actor = vtk.vtkActor()
        self.actor.SetMapper(self.mapper)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

From: det3d

求截面积

一下这个代码是常用的方法:

    crossSectionProperties = vtk.vtkMassProperties()
    crossSectionProperties.SetInputData(crossSectionPolyData)
    currentSurfaceArea = crossSectionProperties.GetSurfaceArea()
1
2
3

可是得到的结果似乎不对:
1

如上图:17*7=119
❓😭为啥呢?🙅🏻‍♀️🙅🏻‍♀️🙅🏻‍♀️

回归Slicer

PerkLab/SlicerSandbox/blob/90320348677225ae86bb54d0dea563af55c5bcae/SegmentCrossSectionArea/SegmentCrossSectionArea.py#L494-L496 2

logic = SegmentCrossSectionAreaLogic()

logic.run(segmentationNode, masterVolumeNode, "slice", tableNode, plotChartNode)

logic.showChart(plotChartNode)
1
2
3
4
5

If you run the code from a different file then of course you need to import the module or the classes that you use from them. For example, you can import the logic class by calling:

from SegmentCrossSectionArea import SegmentCrossSectionAreaLogic
logic = SegmentCrossSectionAreaLogic(),
1
2

Clipped from Compute surface area in segment based on Hounsfield units (CT-images) - Support - 3D Slicer Community at 2022-08-03.

<未完待续>