Getting points back from convexhull/trisurf, or 'how to find the closest point on a 3d surface to a given point.

Question

Cameron 2024-1-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2076231-getting-points-back-from-convexhull-trisurf-or-how-to-find-the-closest-point-on-a-3d-surface-to-a

评论： Cameron 2024-2-1

I'm trying to find the outside surface of a 3D matrix (an MRI of the scalp), The matrix contains all the points of the scalp and I need to be able to calculate the distance to the outside surface from a given internal coordinate.

If I use a delaunay triangulation and create a convexhull of those points I can successfully visualize just the outside surface, but I'm not sure how to a) get those points back in the true coordinate system/b) get the closest point on the surface of the formed convex hull to a given coordinate. Figuring out a) is not necessary if I can directly find b). If there's another way and this makes no sense at all, I'm open to suggestion. TIA

% rcv, or [r c v] is a 75,120 x 3 matrix
DT = delaunayTriangulation([r c v]);
[K,~] = convexHull(DT);
trisurf(K,DT.Points(:,1),DT.Points(:,2),DT.Points(:,3))

Home - The XY Problem