MATLAB: 3D plane plotting restricted by 3 points

3d plane

how can plot a 3D plane restricted among 3 points…???.I mean the plane should be restricted by 3 lines formed by those 3 points

Best Answer

Equation of a plane is determined uniquely by any 3 (noncollinear) points lying on the plane. Based on your question, it sounds like you dont care about equation of the plane and just want to visualize region of a plane enclosed by 3 points (i.e., a triangle). Here is an example of how to do this:

% Vertex coordinates
p1=[0 0 0];
p2=[2 0 0];
p3=[1 sqrt(3/2) sqrt(3/2)];
% Plot trianle using 'patch'
figure('color','w')
h=patch('Faces',1:3,'Vertices',[p1;p2;p3]);
set(h,'FaceColor','r','EdgeColor','k','LineWidth',2,'FaceAlpha',0.5)
axis equal vis3d
view([30 30])
xlabel('x','FontSize',20)
ylabel('y','FontSize',20)
zlabel('z','FontSize',20)

Related Solutions

MATLAB: Vertex Normals – what is their origin point

The origin of the vector is the vertex it is the normal for.

MATLAB: Find center of a plane and project center point perpendicular to plane

As already pointed out by Walter Roberson, 4 points cannot be coplanar. Assuming that they are, you may try this

clear variables, close all
% three random points in 3d
P = rand(3,3);
% vectors
V1 = P(2,:)-P(1,:);
V2 = P(3,:)-P(1,:);
% add one point on the plane defined by the previous three points
P = [P; P(1,:)+V1+V2];
% plot points
figure, hold on, axis equal
plot3(P(:,1),P(:,2),P(:,3),'o');
quiver3(P(1,1),P(1,2),P(1,3),V1(1),V1(2),V1(3),'AutoScale','off')
quiver3(P(1,1),P(1,2),P(1,3),V2(1),V2(2),V2(3),'AutoScale','off')
% plane center
B0 = mean(P,1);
% plot

plot3(B0(1),B0(2),B0(3),'*');
% orthogonal vector
W = cross(V2,V1);
% unit vector
U = W/sqrt(sum(W.^2,2));
% project B by the distance k
k = 2;
B = B0+k*U;
% plot
quiver3(B0(1),B0(2),B0(3),k*U(1),k*U(2),k*U(3),'AutoScale','off');
plot3(B(1),B(2),B(3),'s');

Basically two vectors are created from the first three points, assuming the first point as reference. The orthogonal direction is obtained with a cross product of these vectors. Note that you can control the positive side by changing the order of the cross product.

Best Answer

Related Solutions

MATLAB: Vertex Normals – what is their origin point

MATLAB: Find center of a plane and project center point perpendicular to plane

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