Development of the Korean Spine Database and Automatic Surface Mesh Intersection Algorithm for Constructing e-Spine Simulator

Algorithm 2

Node generation algorithm on the intersection curve to prevent the change of implant model.

Input: 𝐶 (Intersection curve), 𝑃 (Intersection point)

Output:  𝐸_hard (Hard edges), 𝑉_hard (Hard points)

FIND  𝑑_min (minimum distance between 𝑃_𝑘 and 𝑃_𝑘+1,

   𝑃_𝑘 and 𝑃_𝑘+1 are points on the vertexes or edges of 𝐹_implant);

LET  𝑃₀ = get first vertex in 𝐶;

FOR  𝑖=0; 𝑖 < end of index 𝑃

   IF  𝑇(𝑃_𝑖,𝐹) = (𝐹_implant,𝑟,𝑛) (where = 0, 1 ∣ 𝑛 = 0, 1, 2)

      LET  𝑃₁=𝑃_𝑖;

      IF distance between 𝑃₀ and 𝑃₁ > 𝑑_max×𝑘 (user variable)

       FOR  𝑗=0; distance between 𝑃_0−𝑗 and 𝑃₁ > 𝑑_min×𝑘; 𝑗++

         LET  𝑃_0−𝑗+1 = Create new point onto 𝐶;

         LET  𝑆_new = Create new segment (𝑃_0−𝑗,𝑃_0−𝑗+1);

         INSERT  𝑃_0−𝑗+1 into 𝑉_hard;

         INSERT  𝑆_new into 𝐸_hard;

       END

      LET  𝑃₀=𝑃₁;

END