Problem 45220. Find triangles from edge
First input is T, a Triplet list of indices -whom each row actually contains the three indices of a triangle vertices-. size(T) = [nb_triangles, 3]. Second input is e = [e1, e2], a row vector, couple of indices. Output S is the triplet list of indices which Share the edge e. For instance, if
e = [2, 4]
and T a tetrahedron
T = [1, 2, 3;... 1, 3, 4;... 1, 2, 4;... 2, 3, 4]
then the output of the function is
S = [1, 2, 4;... 2, 3, 4]
since both triangles [1, 2, 4] and [2, 3, 4] contain the edge [2, 4].
Conditions :
- If the edge is not part of any triangle in the list, the function must of course return the empty set, [].
- Edges are symmetric : [e1, e2] is the same edge as [e2, e1]
- Order of rows / edges in the output doesn't matter.
- Triangle indices are assumed always to be sorted in ascending order, T = [t1, t2, t3] with t1 < t2 < t3.
- Every indices are positive, distinct integers.
Solution Stats
Problem Comments
-
2 Comments
Info : T is actually a triangulation -list of triangles-, in which each index corresponding to the row index of a vertex in another list -a vertices list-, it is a widely used technique used to store and write triangular meshes in mesh processing. Here below the example is a tetrahedron -4 facets-.
I actually realize this problem looks like a lot to my second problem, "Find a common edge" ( https://fr.mathworks.com/matlabcentral/cody/problems/45218-find-a-common-edge ) ...
Solution Comments
Show commentsProblem Recent Solvers29
Suggested Problems
-
Select every other element of a vector
33872 Solvers
-
457 Solvers
-
Set the array elements whose value is 13 to 0
1377 Solvers
-
90 Solvers
-
Given a square and a circle, please decide whether the square covers more area.
1211 Solvers
More from this Author9
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!