surface area of a 3D surface

21 次查看（过去 30 天）
UNK
UNK 2016-3-6
编辑： Jerry Campbell 2020-10-28
I have data for 3D points and I have made a surface using these points. Is there a way to get surface area of this 3D surface.
Thanks

请先登录，再回答此问题。

采纳的回答

Roger Stafford
Roger Stafford 2016-3-6
If you know the 3D coordinates of each of the three vertices for each triangle in your diagram, then just take the sum of all the triangles' areas.
For example, if P1, P2, and P3 are 3D coordinate vectors of the three respective vertices of some particular triangle, then its area is given by:
AreaP1P2P3 = 1/2*norm(cross(P2-P1,P3-P1));
  2 个评论
M.S. Khan
M.S. Khan 2020-8-24
Hi Rogar, if P1, P2............................Pn, then how will we proceed. Please i have shared same question in the forum. Could you please guide me how to proceed. Regards
Jerry Campbell
Jerry Campbell 2020-10-28
编辑：Jerry Campbell 2020-10-28
Hi M. S.
I created a simple Cube with sides of 100mm in AutoCad then exported the STL file
I then used the following code to calculate the volume and surface area of the cube.
% Create PDE Model
UnitCubeModel = createpde();
% Import STL file into Geometry of Model
UnitCubeModelGeometry = importGeometry(UnitCubeModel,'Unit Cube 100mm v1.stl');
% Generate Mesh for Model
UnitCubeMesh = generateMesh(UnitCubeModel);
% V for vertices and F for the facets
% allDisplayFaces is backward compatible method of the Geometry Object
[F, V] = UnitCubeModelGeometry.allDisplayFaces();
% Perform cross product across all the Facets and Vertices in the Model
a = V(F(:, 2), :) - V(F(:, 1), :);
b = V(F(:, 3), :) - V(F(:, 1), :);
c = cross(a, b, 2);
% Calculate Surface Area and Volume of Model
modelSurfaceArea = 1/2 * sum(sqrt(sum(c.^2, 2)));
modelVolume = volume(UnitCubeMesh);
% Plot the PDE Model
pdegplot(UnitCubeModel,'FaceLabels','on','FaceAlpha',0.5);
% Display the Volume and Surface Area
disp("Volume of Model = " + modelVolume);
disp("The surface area of the Model = " + modelSurfaceArea);

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 Geometry and Mesh 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