Hi everyone, I consider myself a beginner in MATLAB so bear with me if the answer to my question is an obvious one. Phi=0:pi/100:2*pi; Theta=0:pi/100:2*pi; [PHI,THETA]=meshgrid(Phi,Theta); R=(1 + cos(PHI).*cos(PHI)).*(1 + cos(THETA).*cos(THETA)); [X,Y,Z]=sph2cart(THETA,PHI,R); surf(X,Y,Z); %display hold on; x1=-4:.1:4; [X1,Y1] = meshgrid(x1); a=1.8; b=0; c=3; d=0; Z1=(d- a * X1 - b * Y1)/c; shading flat; surf(X1,Y1,Z1); I have written this code which plots a 3d cartesian plot of a plane intersecting a peanut shaped object at an angle. I need to get the intersection of these on 2D (going to be the outline of a peanut, but a bit skewed since the intersection happens at an angle), but don't know how. Thanks