So, I'm attempting to programm orbit in Unity game engine. So I need equation that shows r and phi depending on time. Equation for gravitational potential is U(r)=-k/r+M^2/(2*μ*r^2). Force is -1*derivation of U(r) by r. So I get lots of stupid stuff. If anybody could help me to integrate this equation to get r(t) I would be grateful.