how to create 3D spherical object ?

i have code for peak object that is shown in image matrix form and i want to generate spherical object using 'sphere' function so how to write code for sphere while for peak, code is given below; m=1000; n=1000; % object [x,y,z]=peaks; z=imresize(z,[m,n]); Q=exp(1i*z*2); imshow(z,[]),impixelinfo;