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-- [[arielschwartz]] <<DateTime(2018-03-02T17:55:01Z)>> some users may benefit from seeing the geometry generation page in reverse order. Beginning with the component specific procedures, with links to instructions for Laplacian Smoothing, Taubin smoothing, etc. This way they can follow along with the instructions applicable to the part they are working with. Alternatively, a paragraph at the beginning of the page explaining the layout of this page (with links) will give users an idea of what they are reading before they begin.

This is the discussion page of Specifications/GeometryGeneration. Please provide your input in regard to this specification

  • by editing this page, or
  • by responding to relevant forum entry, or

  • by sending an e-mail to Ahmet Erdemir, <erdemira@ccf.org>.


Comments

-- aerdemir 2016-04-14 17:41:11 Information below was ported from the main specifications page. It illustrates various iterations for smoothing, etc.

-- arielschwartz 2018-03-02 17:55:01 some users may benefit from seeing the geometry generation page in reverse order. Beginning with the component specific procedures, with links to instructions for Laplacian Smoothing, Taubin smoothing, etc. This way they can follow along with the instructions applicable to the part they are working with. Alternatively, a paragraph at the beginning of the page explaining the layout of this page (with links) will give users an idea of what they are reading before they begin.


Following are examples (oks001) of distance maps (using MeshLab: Hausdorf distance) between various pairs of surfaces to assess:

  1. spatial error between corresponding surfaces with varying levels of smoothing/refinement
  2. distance between different model components (e.g. femur vs. femur cartilage, BACK SURFACE)
  3. thickness of model components (e.g. cartilage):

To map tissue thicknesses (e.g. cartilage), opposing surfaces (i.e. BACK SURFACE, FRONT SURFACE) from a manifold (i.e. watertight) STL mesh were split into two complementary, shell STL mesh sets using Blender.

NOTE: all units are displayed in mm.

Smoothing Errors

UNSMOOTHED vs. SMOOTHED:

  • femur cartilage, BACK SURFACE (REF; unsmoothed) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7; ISO 10)
  • femur cartilage, FRONT SURFACE (REF; unsmoothed) vs. femur cartilage, FRONT SURFACE (VCG smoothed, 0.7; ISO 10)
    • oks001_FMC_vs_FMC_VCG_0.7_ISO_10

      oks001_FMC_vs_FMC_VCG_0.7_ISO_10_INF

Distance between Model Components

FEMUR vs. FEMUR CARTILAGE:

  • femur (REF; VCG smoothed, 0.7; ISO, 10) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7; ISO, 10)
    • oks001_FMB_VCG_0.7_ISO_10_vs_FMC_SAME_AI

FEMUR CARTILAGE vs. FEMUR:

  • femur cartilage (REF; VCG smoothed, 0.7; ISO, 10) vs. femur (VCG smoothed, 0.7; ISO, 10)
    • oks001_FMC_VCG_0.7_ISO_10_vs_FMB_SAME

    NOTE: this visualized distance on femur cartilage from the femur bone boundary can be used to find a cutoff value for generating a node set to tie nodes on the back surface of the femur cartilage to the rigid body femur.

Tissue Thickness

FEMUR CARTILAGE THICKNESS (UNSMOOTHED):

  • femur cartilage, BACK SURFACE (REF; UNSMOOTHED) vs. femur cartilage, FRONT SURFACE (UNSMOOTHED)
  • femur cartilage, FRONT SURFACE (REF; UNSMOOTHED) vs. femur cartilage, BACK SURFACE (UNSMOOTHED)
    • oks001_FMC_UNSMOOTHED_BACK_vs_FMC_SAME_FRONT.png

      oks001_FMC_UNSMOOTHED_FRONT_vs_FMC_SAME_BACK.png

FEMUR CARTILAGE THICKNESS (VCG smoothed, 0.7):

  • femur cartilage, BACK SURFACE (REF; VCG smoothed, 0.7) vs. femur cartilage, FRONT SURFACE (VCG smoothed, 0.7)
  • femur cartilage, FRONT SURFACE (REF; VCG smoothed, 0.7) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7)
    • oks001_FMC_VCG_0.7_BACK_vs_FMC_SAME_FRONT

      oks001_FMC_VCG_0.7_FRONT_vs_FMC_SAME_BACK_INF

FEMUR CARTILAGE THICKNESS (VCG smoothed, 0.7; ISO, 10):

  • femur cartilage, BACK SURFACE (REF; VCG smoothed, 0.7; ISO, 10) vs. femur cartilage, FRONT SURFACE (VCG smoothed, 0.7; ISO, 10)
  • femur cartilage, FRONT SURFACE (REF; VCG smoothed, 0.7; ISO, 10) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7; ISO, 10)
    • oks001_FMC_VCG_0.7_ISO_10_BACK_vs_FMC_SAME_FRONT

      oks001_FMC_VCG_0.7_ISO_10_FRONT_vs_FMC_SAME_BACK_INF

FEMUR CARTILAGE THICKNESS (LVTIT):

  • femur cartilage, BACK SURFACE (REF; LVTIT) vs. femur cartilage, FRONT SURFACE (LVTIT)
  • femur cartilage, FRONT SURFACE (REF; LVTIT) vs. femur cartilage, BACK SURFACE (LVTIT)
    • oks001_FMC_LVTIT_BACK_vs_FMC_SAME_FRONT.png

      oks001_FMC_LVTIT_FRONT_vs_FMC_SAME_BACK.png

NOTE: spurious distances (0.0 mm, which are known not to be correct) are present only in the FRONT SURFACE (REF) vs BACK SURFACE, despite similar relative normal directions between reference and measured surfaces!!!


Specifications/GeometryGeneration/Discussion (last edited 2018-05-18 18:19:34 by arielschwartz)