well hopefully you know some introductory physics. All thrown objects follow the path of a parabola, defined by
x=x0+Vi*t+1/2at^2
where x is the total distance, x0 is the starting position, Vi is the initial velocity a is the acceleration and t is the time.
You apply the same equation for the y, except using -9.8 for acceleration.
once that's modelled, you can set how you would like the grenade to bounce off an object. which would be half a prabola in the other direction. hopefully that'll get oyu started.
x=x0+Vi*t+1/2at^2
where x is the total distance, x0 is the starting position, Vi is the initial velocity a is the acceleration and t is the time.
You apply the same equation for the y, except using -9.8 for acceleration.
once that's modelled, you can set how you would like the grenade to bounce off an object. which would be half a prabola in the other direction. hopefully that'll get oyu started.