Grid pattern
The volume of the cone of base radius R and height h
Vcone = pi*R^2*h/3
Assuming you dsicretize by small volume (dx x dx x dx), you 'll get
N ~ Vcone/dx^3. So if you want an approximative of N with grid pattern:
% Cone parameters
R = 10;
h = 10;
N = 10000;
dx = (pi*R^2*h/3/N)^(1/3);
rvec = linspace(-R,R,ceil(2*R/dx));
hvec = linspace(0,h,ceil(h/dx));
[X,Y,Z] = ndgrid(rvec,rvec,hvec);
is_in_cone = (X.^2+Y.^2) <= (R/h*(h-Z)).^2; % Edit bug fix
Xc = X(is_in_cone);
Yc = Y(is_in_cone);
Zc = Z(is_in_cone);
figure(3)
pointsize = 3,
scatter3(Xc, Yc, Zc, pointsize, 'filled')
axis equal
numel(Xc) % should be close to N
