I want to plot a 3D function which is a summation of some other 3D functions (i.e. g(x,y) = f1(x,y) + f2(x,y) + ...). If I add them parametrically as they are, it will be a big parametric function of (x,y) and plotting takes a long time. To overcome the problem, I am thinking of calculating each function (e.g. f1(x,y)) and store its results in a matrix for each, and then sum up all stored results. First of all, please let me know if there is an alternative way to take. If not, please let me know how I can best plot that data (summation of functions)? pointPlot3d just plots them in dot fashion which is not clear to follow. How do I plot them as plot3d does, but with data?