4d plot in order to create a surface with density from 4 vectors ( coordinates of the dots). X, Y, Z and C is the color.

Hi,

I wanto to create a 4d plot, like isosurface. The data is attached. 4 vectors, xyz and color.

The problem is that I only have 4 vectors, XYZ is position in the space which creates the object and c is the color of that point.

I am kind of lost. Maybe I need to use meshgrid but the vectors has 37k points.

Thanks

[darova]

Show your attempts

Answer 1

[Akira Agata]

OK. Then, how about the following?

% Load data
load('object.mat')

% Create meshgrid
[xq, yq, zq] = meshgrid(min(x):5:max(x),min(y):5:max(y),min(z):5:max(z));

% Assign data to the grid point
cq = nan(size(xq));
[~, pos] = ismember([x,y,z],[xq(:),yq(:),zq(:)],'rows');
cq(pos) = c;

% Find boundary points location
k = boundary(x,y,z,1);

% Create isosurface levels and color
N = 8;
color = jet(N);
v = linspace(min(c),max(c),N);

% Visualize the result
figure
hold on
for kk = 1:N
    p = patch(isosurface(xq,yq,zq,cq,v(kk)),...
        'FaceColor',    color(kk,:),...
        'EdgeColor',    'none',...
        'FaceAlpha',    0.2);
    isonormals(xq,yq,zq,cq,p)
end
trisurf(k,x,y,z,...
    'Facecolor',     'b',...
    'FaceAlpha',    0.1,...
    'Edgecolor',    'none')
view(120,30); 
camlight('headlight')
lighting gouraud
grid on

[Rafael Freire]

THAT IS PERFECT!!!!!! Exactly what I needed. Thank you very very much!!!! I spent more than a week trying to solve this.

[Rafael Freire]

BTW, many people are having the same issue. I read tons of Q&A and doubts regarding this issue during this week and all of them were unclear how solve it. Once again thank you very much. Maybe it sounds good to create a topic on it."From 4d xyzc coordinates to a surface plot"

Answer 2

[Akira Agata]

How about simply using scatter3 function, like:

load('object.mat')

figure
scatter3(x,y,z,[],c,'.')
colorbar

[Rafael Freire]

HI.

Thank you for your answer. I arealdy tryed that but i didint work.

The final result that I need is like the pic below.