I was reading "Introduction to Game Development - second edition" page 379, it was talking about terrain collision detection and it gave me this formula, given you have collision X, Z, normal and a point... Although It didn't explain it well, so I am not 100% certain I am interpreting the equation properly.

Is this correct:

given Qx, Qz, P1(X, Y, Z) and a normal(X, Y, Z)

Qy = (-(Nx*Qx) - (Nz*Qz)+(N (dot product) P1))/Ny

I know its a stupid question, It would just kill me if I implemented it wrong

Thanks