In my case, simple 2d quads.

Quote:Original post by Jacob Roman
Ok, well let's say I wanted y = y0 + a * t, which is a basic physics equation. Would it be ok for the function f(t,y) to return y0 + a * t, assuming I had y0 as an arguement?

No. f(t,y) does NOT produce a value for y at a particular time! It produces the DERIVATIVE of y with respect to t. So, if you wanted the expression y = y0+a*t, the derivative dy/dt would be a, so you would have f(t,y) == a.

I really think you need to learn more about Ordinary Differential Equations before you tackle ODE solvers like RK4. RK4 as a tool will be useless to you until you understand what it's meant to do.