How can I plot a 3D matrix as a cube with different transparent colors for the values?

Hello,

I have a 3D-Matrix consisting only of values 0,1,2 and 3. Is it possible to plot the matrix so it looks like a big, transparent rubic´s cube, where every value gets its own colour? Like imagesc(...) but only in 3D.

Thanks a lot!

[darova]

Did you try scatter3()?

[BananaBandana]

Hey,

But scatter3() uses vectors as inputs, right?

But I have a (n x n x n) Matrix. This wouldn't work I guess, would it?

[darova]

You have only one matrix 3D?

[BananaBandana]

yes, one threedimensional Matrix

Answer 1

[darova]

Since you have matrix of 0,1,2,3 and don't have coordinates you can create them

Assume A - is you matrix (N x N x N)

% (:) - colon operator (make vector from matrix of length N*N*N)
[X,Y,Z] = meshgrid(1:N);
scatter3(X(:),Y(:),Z(:),5,A(:))

[BananaBandana]

Ah, this goes into the right direction. But if I do it like you did it, then I get a marker at the nodes of the matrix. But I wanted to get a big cube consisting of (N x N x N) smaller cubes, where every cube resembles the equivalent matrix value with a color. Similar to this picture

I could not find a way to do it like this.

Thanks!

[darova]

Create one cube using patch() (or fill3()) then copy it using for loop

clear,clc,cla

x1 = [1 1 1 1]'/2;       % right wall
y1 = [1 1 -1 -1]'/2;
z1 = [1 -1 -1 1]'/2;

x2 = [1 1 -1 -1]'/2;     % top wall
y2 = [-1 1 1 -1]'/2;
z2 = [1 1 1 1]'/2;

x3 = x2;                 % bottom wall
y3 = y2;
z3 = -z2;

X = [x1 x2 x3];
Y = [y1 y2 y3];
Z = [z1 z2 z3];

patch(X,Y,Z,'b')
alpha(0.5)
axis equal

I succeded

[BananaBandana]

Thanks!

it worked! But I realized that it takes a lot of time to process for a bigger matrix and therefore is probably is not useable for my case :( I will probably have to think of a different way to visualize it... but thats a different question