%!TEX lualatex

\documentclass[border=1pt]{standalone}
\usepackage{luamplib}

\begin{document}

%https://tex.stackexchange.com/questions/648153/how-to-create-triangular-pyramid-of-oranges-using-tikz
\begin{mplibcode}
	% first set up the isometric projection
	numeric alpha, beta, ipca, ipsa, ipcb, ipsb, ipscale;
	alpha = -20;
	beta = 10;
	ipca = cosd(alpha); ipsa = sind(alpha);
	ipcb = cosd(beta); ipsb = sind(beta);
	ipscale := 16;
	
	% this macro projects 3D to 2D (isometrically)
	vardef p(expr x, y, z) =
	(x * ipcb - z * ipsb, y * ipca + x * ipsa * ipsb + z * ipsa * ipcb) scaled ipscale
	enddef;
	
	% now make an orange picture
	color a, b;
	b = (0.99608,0.90196,0.80784);
	a = (0.54902,0.17647,0.015686);
	path C, c; numeric n; n = 16;
	C = fullcircle scaled ipscale;
	c = fullcircle scaled 1/2 shifted (-3,3);
	picture orange;
	orange = image(for i=0 upto n:
	fill interpath(i/n, C, c) withcolor (i/n)[a,b];
	endfor);
	
	beginfig(1);
	for n = 6 :  % draw four stacks of oranges...
	picture stack; stack = image(
	for k = n-1 downto 0:
	for j = k downto 0:
	for i = 0 upto j:
	draw orange shifted p(i - 0.5 j, -0.866 k, -0.866 j + 0.5 k);
	endfor
	endfor
	endfor
	);
	numeric x; x = 42n * sqrt(n);
	draw stack shifted (x, 8n);
	endfor
	endfig;
\end{mplibcode}

\end{document}