How to create randomly placed points within a 3D figure?

So I have a function of a figure, and I am trying to generate at least a hundred points inside the figure. I have no problem generating the points itself but I can't seem to make them stay within the figure, some of the points go out of the figure which is not what I intended

clear; 

close all; 

clc;

%heart

[X,Y,Z]=meshgrid(-1.5:0.03:1.5);

F=(((X.^2) + (9/4).*(Y.^2) + Z.^2-1).^3+(-X.^2 .* Z.^3 -(9/80).*Y.^2.*Z.^3));%function defining a heart

patch(isosurface(X, Y, Z, F, 0), 'FaceColor', 'w', 'FaceAlpha',.3,'EdgeAlpha',.1);

view(3)

xlabel('x');

ylabel('y');

zlabel('z');

axis equal;

grid on;

%
hold on;     

%random points

x = -1 + (1+1)*rand(1,100); %x-coordinate of a point

y = -0.6 + (0.6+0.6)*rand(1,100); %y-coordinate of a point

z = -0.8 + (1.2+0.8)*rand(1,100); %z-coordinate of a point

scatter3(x, y, z, 'MarkerFaceColor','b','MarkerEdgeColor','b');

hold off

Answer 1

[David Goodmanson]

Hello Frankie,

You have to select random points that are inside the heart and fortunately you already have the function that does that.

% pick plenty of random points
x = -1 + (1+1)*rand(1,500); %x-coordinate of a point
y = -0.6 + (0.6+0.6)*rand(1,500); %y-coordinate of a point
z = -0.8 + (1.2+0.8)*rand(1,500); %z-coordinate of a point

%function defining a heart
F1=(((x.^2) + (9/4).*(y.^2) + z.^2-1).^3+(-x.^2 .* z.^3 -(9/80).*y.^2.*z.^3));

ind = F1<0;                   % index for points inside the isosurface
x = x(ind);  x = x(1:100);    % pick 100 of those points
y = y(ind);  y = y(1:100);
z = z(ind);  z = z(1:100);

scatter3(x, y, z, 'MarkerFaceColor','b','MarkerEdgeColor','b');

hold off

[KSSV]

Nice solution.....I could not get this logic....I learned something today.......

[Frankie]

Thank you! I kind of had an idea of how to do it but could not translate it into code.