Extract Centerline fails when calculating the centerline with "Tree" window

Support
, ,
1

Hello,

I am encountering the following error while computing the Centerline Model (from window tab Tree) from a segmentation node:
Warning: In /home/davagh/built/Slicer-build041022/VTK/Filters/Core/vtkDelaunay3D.cxx, line 518
vtkDelaunay3D (0x55ecfe6ff650): 241 degenerate triangles encountered, mesh quality suspect
Error while constructing cell map: Invalid cell size for polys.

The following are few tests I made for trying to find a possible solution:

  • If no smoothing is applied to the segmentation, I am able to generate the below Centerline Network using the Auto-Detect option for detecting the end points:

    image_00033
    image_000331174×906 130 KB

  • If no smoothing is applied to the segmentation, I am able to generate the below Centerline Network using the 4 displayed control points:

    image_00031
    image_000311174×906 161 KB

  • If 0.3 smoothing is applied (from Segment Editor), I am able to generate the green Centerline Model (from window tab Tree) using the same 4 control points:

    image_00032
    image_000321174×906 126 KB

It seems that smoothing the surface could work around this problem. However, there are few cases where a smoothing is not the preferred choice for surgeons (like in this case).
I am wondering: which factor could define a “good enough” smoothing, in order not to fail the extractCenterline method?

I appreciate if you could provide any feedback on this or even point out a vmtk link/documentation that could help me to better understand the problem. :smile:

OS: Ubuntu 22.04.1 LTS
Graphics: NVIDIA [GeForce RTX 3090]

2 Likes