How to efficiently compute normal to a surface given surface points

35 次查看（过去 30 天）
alegio20
alegio20 2021-3-8
评论： darova 2021-3-8
Hi everyone,
I am struggling to understand how to compute normal to a surface on ML.
I have a very simple geometry made by a cone divided both in height and along the circumference, and what I would like as outputs for every area in which the cone is divided are:
  • The centroid of every single area;
  • The normal to the area centered on the centroid.
The output I would like is formed by a matrix for the centroids and a matrix for the normals in which each row is formed by a triplet X, Y, Z of the coordinates and values of the centroids and normals respectively.
I attach part of the code for generating a simple cone.
n = 36; % Number of divisions along the circumference
hi = 1; % Number of divisions along the height of the cone (needed for another part of the code)
H = 5; % Height of the cone
r = zeros (1,H/hi);
R = 3; % Base radius
for i = 1:H/hi
r(i) = (1-i*hi/H)*R;
end
[x,y,z] = cylinder(r,n);
z = z*H;

请先登录，再回答此问题。

采纳的回答

darova
darova 2021-3-8
try surfnorm
  2 个评论
alegio20
alegio20 2021-3-8
编辑：alegio20 2021-3-8
Thanks, i have alredy tried surfnorm but it doesn't calculates where I need to and just calculates it at intesections between areas. Not in the centers.
darova
darova 2021-3-8
You can calculate vector field (u,v,w) and interpolate it where you need
[u,v,w] = surfnorm(x,y,z);
u1 = interp2(x,y,u,x1,y1);
v1 = interp2(x,y,v,x1,y1);
w1 = interp2(x,y,w,x1,y1);

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Geometric Transformation and Image Registration 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by